Date: 2026-06-01T23:13:23+00:00

Actual source code: dm.c

      1: #include <petscvec.h>
      2: #include <petsc/private/dmimpl.h>
      3: #include <petsc/private/dmlabelimpl.h>
      4: #include <petsc/private/petscdsimpl.h>
      5: #include <petscdmplex.h>
      6: #include <petscdmceed.h>
      7: #include <petscdmfield.h>
      8: #include <petscsf.h>
      9: #include <petscds.h>

     11: #ifdef PETSC_HAVE_LIBCEED
     12: #include <petscfeceed.h>
     13: #endif

     15: PetscClassId DM_CLASSID;
     16: PetscClassId DMLABEL_CLASSID;
     17: PetscLogEvent DM_Convert, DM_GlobalToLocal, DM_LocalToGlobal, DM_LocalToLocal, DM_LocatePoints, DM_Coarsen, DM_Refine, DM_CreateInterpolation, DM_CreateRestriction, DM_CreateInjection, DM_CreateMatrix, DM_CreateMassMatrix, DM_Load, DM_View, DM_AdaptInterpolator, DM_ProjectFunction;

     19: const char *const DMBoundaryTypes[]          = {"NONE", "GHOSTED", "MIRROR", "PERIODIC", "TWIST", "DMBoundaryType", "DM_BOUNDARY_", NULL};
     20: const char *const DMBoundaryConditionTypes[] = {"INVALID", "ESSENTIAL", "NATURAL", "INVALID", "LOWER_BOUND", "ESSENTIAL_FIELD", "NATURAL_FIELD", "INVALID", "UPPER_BOUND", "ESSENTIAL_BD_FIELD", "NATURAL_RIEMANN", "DMBoundaryConditionType",
     21:                                                 "DM_BC_",  NULL};
     22: const char *const DMBlockingTypes[]          = {"TOPOLOGICAL_POINT", "FIELD_NODE", "DMBlockingType", "DM_BLOCKING_", NULL};
     23: const char *const DMPolytopeTypes[] =
     24:   {"vertex",  "segment",      "tensor_segment", "triangle", "quadrilateral",  "tensor_quad",  "tetrahedron", "hexahedron", "triangular_prism", "tensor_triangular_prism", "tensor_quadrilateral_prism", "pyramid", "FV_ghost_cell", "interior_ghost_cell",
     25:    "unknown", "unknown_cell", "unknown_face",   "invalid",  "DMPolytopeType", "DM_POLYTOPE_", NULL};
     26: const char *const DMCopyLabelsModes[] = {"replace", "keep", "fail", "DMCopyLabelsMode", "DM_COPY_LABELS_", NULL};

     28: /*@
     29:   DMCreate - Creates an empty `DM` object. `DM`s are the abstract objects in PETSc that mediate between meshes and discretizations and the
     30:   algebraic solvers, time integrators, and optimization algorithms in PETSc.

     32:   Collective

     34:   Input Parameter:
     35: . comm - The communicator for the `DM` object

     37:   Output Parameter:
     38: . dm - The `DM` object

     40:   Level: beginner

     42:   Notes:
     43:   See `DMType` for a brief summary of available `DM`.

     45:   The type must then be set with `DMSetType()`. If you never call `DMSetType()` it will generate an
     46:   error when you try to use the `dm`.

     48:   `DM` is an orphan initialism or orphan acronym, the letters have no meaning and never did.

     50: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMType`, `DMDACreate()`, `DMDA`, `DMSLICED`, `DMCOMPOSITE`, `DMPLEX`, `DMMOAB`, `DMNETWORK`
     51: @*/
     52: PetscErrorCode DMCreate(MPI_Comm comm, DM *dm)
     53: {
     54:   DM      v;
     55:   PetscDS ds;

     57:   PetscFunctionBegin;
     58:   PetscAssertPointer(dm, 2);

     60:   PetscCall(DMInitializePackage());
     61:   PetscCall(PetscHeaderCreate(v, DM_CLASSID, "DM", "Distribution Manager", "DM", comm, DMDestroy, DMView));
     62:   ((PetscObject)v)->non_cyclic_references = &DMCountNonCyclicReferences;
     63:   v->setupcalled                          = PETSC_FALSE;
     64:   v->setfromoptionscalled                 = PETSC_FALSE;
     65:   v->ltogmap                              = NULL;
     66:   v->bind_below                           = 0;
     67:   v->bs                                   = 1;
     68:   v->coloringtype                         = IS_COLORING_GLOBAL;
     69:   PetscCall(PetscSFCreate(comm, &v->sf));
     70:   PetscCall(PetscSFCreate(comm, &v->sectionSF));
     71:   v->labels                    = NULL;
     72:   v->adjacency[0]              = PETSC_FALSE;
     73:   v->adjacency[1]              = PETSC_TRUE;
     74:   v->depthLabel                = NULL;
     75:   v->celltypeLabel             = NULL;
     76:   v->localSection              = NULL;
     77:   v->globalSection             = NULL;
     78:   v->defaultConstraint.section = NULL;
     79:   v->defaultConstraint.mat     = NULL;
     80:   v->defaultConstraint.bias    = NULL;
     81:   v->coordinates[0].dim        = PETSC_DEFAULT;
     82:   v->coordinates[1].dim        = PETSC_DEFAULT;
     83:   v->sparseLocalize            = PETSC_TRUE;
     84:   v->dim                       = PETSC_DETERMINE;
     85:   PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
     86:   PetscCall(DMSetRegionDS(v, NULL, NULL, ds, NULL));
     87:   PetscCall(PetscDSDestroy(&ds));
     88:   PetscCall(PetscHMapAuxCreate(&v->auxData));
     89:   v->dmBC              = NULL;
     90:   v->coarseMesh        = NULL;
     91:   v->outputSequenceNum = -1;
     92:   v->outputSequenceVal = 0.0;
     93:   PetscCall(DMSetVecType(v, VECSTANDARD));
     94:   PetscCall(DMSetMatType(v, MATAIJ));

     96:   *dm = v;
     97:   PetscFunctionReturn(PETSC_SUCCESS);
     98: }

    100: /*@
    101:   DMClone - Creates a `DM` object with the same topology as the original.

    103:   Collective

    105:   Input Parameter:
    106: . dm - The original `DM` object

    108:   Output Parameter:
    109: . newdm - The new `DM` object

    111:   Level: beginner

    113:   Notes:
    114:   For some `DM` implementations this is a shallow clone, the result of which may share (reference counted) information with its parent. For example,
    115:   `DMClone()` applied to a `DMPLEX` object will result in a new `DMPLEX` that shares the topology with the original `DMPLEX`. It does not
    116:   share the `PetscSection` of the original `DM`.

    118:   The clone is considered set up if the original has been set up.

    120:   Use `DMConvert()` for a general way to create new `DM` from a given `DM`

    122: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMSetType()`, `DMSetLocalSection()`, `DMSetGlobalSection()`, `DMPLEX`, `DMConvert()`
    123: @*/
    124: PetscErrorCode DMClone(DM dm, DM *newdm)
    125: {
    126:   PetscSF              sf;
    127:   Vec                  coords;
    128:   void                *ctx;
    129:   MatOrderingType      otype;
    130:   DMReorderDefaultFlag flg;
    131:   PetscInt             dim, cdim, i;
    132:   PetscBool            sparse;

    134:   PetscFunctionBegin;
    136:   PetscAssertPointer(newdm, 2);
    137:   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), newdm));
    138:   PetscCall(DMCopyLabels(dm, *newdm, PETSC_COPY_VALUES, PETSC_TRUE, DM_COPY_LABELS_FAIL));
    139:   (*newdm)->leveldown     = dm->leveldown;
    140:   (*newdm)->levelup       = dm->levelup;
    141:   (*newdm)->prealloc_only = dm->prealloc_only;
    142:   (*newdm)->prealloc_skip = dm->prealloc_skip;
    143:   PetscCall(PetscFree((*newdm)->vectype));
    144:   PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*newdm)->vectype));
    145:   PetscCall(PetscFree((*newdm)->mattype));
    146:   PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*newdm)->mattype));
    147:   PetscCall(DMGetDimension(dm, &dim));
    148:   PetscCall(DMSetDimension(*newdm, dim));
    149:   PetscTryTypeMethod(dm, clone, newdm);
    150:   (*newdm)->setupcalled = dm->setupcalled;
    151:   PetscCall(DMGetPointSF(dm, &sf));
    152:   PetscCall(DMSetPointSF(*newdm, sf));
    153:   PetscCall(DMGetApplicationContext(dm, &ctx));
    154:   PetscCall(DMSetApplicationContext(*newdm, ctx));
    155:   PetscCall(DMReorderSectionGetDefault(dm, &flg));
    156:   PetscCall(DMReorderSectionSetDefault(*newdm, flg));
    157:   PetscCall(DMReorderSectionGetType(dm, &otype));
    158:   PetscCall(DMReorderSectionSetType(*newdm, otype));
    159:   for (i = 0; i < 2; ++i) {
    160:     if (dm->coordinates[i].dm) {
    161:       DM           ncdm;
    162:       PetscSection cs;
    163:       PetscInt     pEnd = -1, pEndMax = -1;

    165:       PetscCall(DMGetLocalSection(dm->coordinates[i].dm, &cs));
    166:       if (cs) PetscCall(PetscSectionGetChart(cs, NULL, &pEnd));
    167:       PetscCallMPI(MPIU_Allreduce(&pEnd, &pEndMax, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    168:       if (pEndMax >= 0) {
    169:         PetscCall(DMClone(dm->coordinates[i].dm, &ncdm));
    170:         PetscCall(DMCopyDisc(dm->coordinates[i].dm, ncdm));
    171:         PetscCall(DMSetLocalSection(ncdm, cs));
    172:         if (dm->coordinates[i].dm->periodic.setup) {
    173:           ncdm->periodic.setup = dm->coordinates[i].dm->periodic.setup;
    174:           PetscCall(ncdm->periodic.setup(ncdm));
    175:         }
    176:         if (i) PetscCall(DMSetCellCoordinateDM(*newdm, ncdm));
    177:         else PetscCall(DMSetCoordinateDM(*newdm, ncdm));
    178:         PetscCall(DMDestroy(&ncdm));
    179:       }
    180:     }
    181:   }
    182:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    183:   PetscCall(DMSetCoordinateDim(*newdm, cdim));
    184:   PetscCall(DMGetCoordinatesLocal(dm, &coords));
    185:   if (coords) {
    186:     PetscCall(DMSetCoordinatesLocal(*newdm, coords));
    187:   } else {
    188:     PetscCall(DMGetCoordinates(dm, &coords));
    189:     if (coords) PetscCall(DMSetCoordinates(*newdm, coords));
    190:   }
    191:   PetscCall(DMGetSparseLocalize(dm, &sparse));
    192:   PetscCall(DMSetSparseLocalize(*newdm, sparse));
    193:   PetscCall(DMGetCellCoordinatesLocal(dm, &coords));
    194:   if (coords) {
    195:     PetscCall(DMSetCellCoordinatesLocal(*newdm, coords));
    196:   } else {
    197:     PetscCall(DMGetCellCoordinates(dm, &coords));
    198:     if (coords) PetscCall(DMSetCellCoordinates(*newdm, coords));
    199:   }
    200:   {
    201:     const PetscReal *maxCell, *Lstart, *L;

    203:     PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    204:     PetscCall(DMSetPeriodicity(*newdm, maxCell, Lstart, L));
    205:   }
    206:   {
    207:     PetscBool useCone, useClosure;

    209:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, &useCone, &useClosure));
    210:     PetscCall(DMSetAdjacency(*newdm, PETSC_DEFAULT, useCone, useClosure));
    211:   }
    212:   PetscFunctionReturn(PETSC_SUCCESS);
    213: }

    215: /*@
    216:   DMSetVecType - Sets the type of vector to be created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    218:   Logically Collective

    220:   Input Parameters:
    221: + dm    - initial distributed array
    222: - ctype - the vector type, for example `VECSTANDARD`, `VECCUDA`, or `VECVIENNACL`

    224:   Options Database Key:
    225: . -dm_vec_type ctype - the type of vector to create

    227:   Level: intermediate

    229: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMGetVecType()`, `DMSetMatType()`, `DMGetMatType()`,
    230:           `VECSTANDARD`, `VECCUDA`, `VECVIENNACL`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`
    231: @*/
    232: PetscErrorCode DMSetVecType(DM dm, VecType ctype)
    233: {
    234:   char *tmp;

    236:   PetscFunctionBegin;
    238:   PetscAssertPointer(ctype, 2);
    239:   tmp = (char *)dm->vectype;
    240:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->vectype));
    241:   PetscCall(PetscFree(tmp));
    242:   PetscFunctionReturn(PETSC_SUCCESS);
    243: }

    245: /*@
    246:   DMGetVecType - Gets the type of vector created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    248:   Logically Collective

    250:   Input Parameter:
    251: . da - initial distributed array

    253:   Output Parameter:
    254: . ctype - the vector type

    256:   Level: intermediate

    258: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMSetMatType()`, `DMGetMatType()`, `DMSetVecType()`
    259: @*/
    260: PetscErrorCode DMGetVecType(DM da, VecType *ctype)
    261: {
    262:   PetscFunctionBegin;
    264:   *ctype = da->vectype;
    265:   PetscFunctionReturn(PETSC_SUCCESS);
    266: }

    268: /*@
    269:   VecGetDM - Gets the `DM` defining the data layout of the vector

    271:   Not Collective

    273:   Input Parameter:
    274: . v - The `Vec`

    276:   Output Parameter:
    277: . dm - The `DM`

    279:   Level: intermediate

    281:   Note:
    282:   A `Vec` may not have a `DM` associated with it.

    284: .seealso: [](ch_dmbase), `DM`, `VecSetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    285: @*/
    286: PetscErrorCode VecGetDM(Vec v, DM *dm)
    287: {
    288:   PetscFunctionBegin;
    290:   PetscAssertPointer(dm, 2);
    291:   PetscCall(PetscObjectQuery((PetscObject)v, "__PETSc_dm", (PetscObject *)dm));
    292:   PetscFunctionReturn(PETSC_SUCCESS);
    293: }

    295: /*@
    296:   VecSetDM - Sets the `DM` defining the data layout of the vector.

    298:   Not Collective

    300:   Input Parameters:
    301: + v  - The `Vec`
    302: - dm - The `DM`

    304:   Level: developer

    306:   Notes:
    307:   This is rarely used, generally one uses `DMGetLocalVector()` or  `DMGetGlobalVector()` to create a vector associated with a given `DM`

    309:   This is NOT the same as `DMCreateGlobalVector()` since it does not change the view methods or perform other customization, but merely sets the `DM` member.

    311: .seealso: [](ch_dmbase), `DM`, `VecGetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    312: @*/
    313: PetscErrorCode VecSetDM(Vec v, DM dm)
    314: {
    315:   PetscFunctionBegin;
    318:   PetscCall(PetscObjectCompose((PetscObject)v, "__PETSc_dm", (PetscObject)dm));
    319:   PetscFunctionReturn(PETSC_SUCCESS);
    320: }

    322: /*@
    323:   DMSetISColoringType - Sets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    325:   Logically Collective

    327:   Input Parameters:
    328: + dm    - the `DM` context
    329: - ctype - the matrix type

    331:   Options Database Key:
    332: . -dm_is_coloring_type (global|local) - see `ISColoringType`

    334:   Level: intermediate

    336: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    337:           `DMGetISColoringType()`, `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    338: @*/
    339: PetscErrorCode DMSetISColoringType(DM dm, ISColoringType ctype)
    340: {
    341:   PetscFunctionBegin;
    343:   dm->coloringtype = ctype;
    344:   PetscFunctionReturn(PETSC_SUCCESS);
    345: }

    347: /*@
    348:   DMGetISColoringType - Gets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    350:   Logically Collective

    352:   Input Parameter:
    353: . dm - the `DM` context

    355:   Output Parameter:
    356: . ctype - the matrix type

    358:   Level: intermediate

    360: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    361:           `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    362: @*/
    363: PetscErrorCode DMGetISColoringType(DM dm, ISColoringType *ctype)
    364: {
    365:   PetscFunctionBegin;
    367:   *ctype = dm->coloringtype;
    368:   PetscFunctionReturn(PETSC_SUCCESS);
    369: }

    371: /*@
    372:   DMSetMatType - Sets the type of matrix created with `DMCreateMatrix()`

    374:   Logically Collective

    376:   Input Parameters:
    377: + dm    - the `DM` context
    378: - ctype - the matrix type, for example `MATMPIAIJ`

    380:   Options Database Key:
    381: . -dm_mat_type ctype - the type of the matrix to create, see `MatType`

    383:   Level: intermediate

    385: .seealso: [](ch_dmbase), `DM`, `MatType`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMGetMatType()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`
    386: @*/
    387: PetscErrorCode DMSetMatType(DM dm, MatType ctype)
    388: {
    389:   char *tmp;

    391:   PetscFunctionBegin;
    393:   PetscAssertPointer(ctype, 2);
    394:   tmp = (char *)dm->mattype;
    395:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->mattype));
    396:   PetscCall(PetscFree(tmp));
    397:   PetscFunctionReturn(PETSC_SUCCESS);
    398: }

    400: /*@
    401:   DMGetMatType - Gets the type of matrix that would be created with `DMCreateMatrix()`

    403:   Logically Collective

    405:   Input Parameter:
    406: . dm - the `DM` context

    408:   Output Parameter:
    409: . ctype - the matrix type

    411:   Level: intermediate

    413: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMSetMatType()`
    414: @*/
    415: PetscErrorCode DMGetMatType(DM dm, MatType *ctype)
    416: {
    417:   PetscFunctionBegin;
    419:   *ctype = dm->mattype;
    420:   PetscFunctionReturn(PETSC_SUCCESS);
    421: }

    423: /*@
    424:   MatGetDM - Gets the `DM` defining the data layout of the matrix

    426:   Not Collective

    428:   Input Parameter:
    429: . A - The `Mat`

    431:   Output Parameter:
    432: . dm - The `DM`

    434:   Level: intermediate

    436:   Note:
    437:   A matrix may not have a `DM` associated with it

    439:   Developer Note:
    440:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with the `Mat` through a `PetscObjectCompose()` operation

    442: .seealso: [](ch_dmbase), `DM`, `MatSetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    443: @*/
    444: PetscErrorCode MatGetDM(Mat A, DM *dm)
    445: {
    446:   PetscFunctionBegin;
    448:   PetscAssertPointer(dm, 2);
    449:   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_dm", (PetscObject *)dm));
    450:   PetscFunctionReturn(PETSC_SUCCESS);
    451: }

    453: /*@
    454:   MatSetDM - Sets the `DM` defining the data layout of the matrix

    456:   Not Collective

    458:   Input Parameters:
    459: + A  - The `Mat`
    460: - dm - The `DM`

    462:   Level: developer

    464:   Note:
    465:   This is rarely used in practice, rather `DMCreateMatrix()` is used to create a matrix associated with a particular `DM`

    467:   Developer Note:
    468:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with
    469:   the `Mat` through a `PetscObjectCompose()` operation

    471: .seealso: [](ch_dmbase), `DM`, `MatGetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    472: @*/
    473: PetscErrorCode MatSetDM(Mat A, DM dm)
    474: {
    475:   PetscFunctionBegin;
    478:   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc_dm", (PetscObject)dm));
    479:   PetscFunctionReturn(PETSC_SUCCESS);
    480: }

    482: /*@
    483:   DMSetOptionsPrefix - Sets the prefix prepended to all option names when searching through the options database

    485:   Logically Collective

    487:   Input Parameters:
    488: + dm     - the `DM` context
    489: - prefix - the prefix to prepend

    491:   Level: advanced

    493:   Note:
    494:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    495:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    497: .seealso: [](ch_dmbase), `DM`, `PetscObjectSetOptionsPrefix()`, `DMSetFromOptions()`
    498: @*/
    499: PetscErrorCode DMSetOptionsPrefix(DM dm, const char prefix[])
    500: {
    501:   PetscFunctionBegin;
    503:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm, prefix));
    504:   if (dm->sf) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sf, prefix));
    505:   if (dm->sectionSF) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sectionSF, prefix));
    506:   PetscFunctionReturn(PETSC_SUCCESS);
    507: }

    509: /*@
    510:   DMAppendOptionsPrefix - Appends an additional string to an already existing prefix used for searching for
    511:   `DM` options in the options database.

    513:   Logically Collective

    515:   Input Parameters:
    516: + dm     - the `DM` context
    517: - prefix - the string to append to the current prefix

    519:   Level: advanced

    521:   Note:
    522:   If the `DM` does not currently have an options prefix then this value is used alone as the prefix as if `DMSetOptionsPrefix()` had been called.
    523:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    524:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    526: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMGetOptionsPrefix()`, `PetscObjectAppendOptionsPrefix()`, `DMSetFromOptions()`
    527: @*/
    528: PetscErrorCode DMAppendOptionsPrefix(DM dm, const char prefix[])
    529: {
    530:   PetscFunctionBegin;
    532:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)dm, prefix));
    533:   PetscFunctionReturn(PETSC_SUCCESS);
    534: }

    536: /*@
    537:   DMGetOptionsPrefix - Gets the prefix used for searching for all
    538:   DM options in the options database.

    540:   Not Collective

    542:   Input Parameter:
    543: . dm - the `DM` context

    545:   Output Parameter:
    546: . prefix - pointer to the prefix string used is returned

    548:   Level: advanced

    550: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMAppendOptionsPrefix()`, `DMSetFromOptions()`
    551: @*/
    552: PetscErrorCode DMGetOptionsPrefix(DM dm, const char *prefix[])
    553: {
    554:   PetscFunctionBegin;
    556:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)dm, prefix));
    557:   PetscFunctionReturn(PETSC_SUCCESS);
    558: }

    560: static PetscErrorCode DMCountNonCyclicReferences_Internal(DM dm, PetscBool recurseCoarse, PetscBool recurseFine, PetscInt *ncrefct)
    561: {
    562:   PetscInt refct = ((PetscObject)dm)->refct;

    564:   PetscFunctionBegin;
    565:   *ncrefct = 0;
    566:   if (dm->coarseMesh && dm->coarseMesh->fineMesh == dm) {
    567:     refct--;
    568:     if (recurseCoarse) {
    569:       PetscInt coarseCount;

    571:       PetscCall(DMCountNonCyclicReferences_Internal(dm->coarseMesh, PETSC_TRUE, PETSC_FALSE, &coarseCount));
    572:       refct += coarseCount;
    573:     }
    574:   }
    575:   if (dm->fineMesh && dm->fineMesh->coarseMesh == dm) {
    576:     refct--;
    577:     if (recurseFine) {
    578:       PetscInt fineCount;

    580:       PetscCall(DMCountNonCyclicReferences_Internal(dm->fineMesh, PETSC_FALSE, PETSC_TRUE, &fineCount));
    581:       refct += fineCount;
    582:     }
    583:   }
    584:   *ncrefct = refct;
    585:   PetscFunctionReturn(PETSC_SUCCESS);
    586: }

    588: /* Generic wrapper for DMCountNonCyclicReferences_Internal() */
    589: PetscErrorCode DMCountNonCyclicReferences(PetscObject dm, PetscInt *ncrefct)
    590: {
    591:   PetscFunctionBegin;
    592:   PetscCall(DMCountNonCyclicReferences_Internal((DM)dm, PETSC_TRUE, PETSC_TRUE, ncrefct));
    593:   PetscFunctionReturn(PETSC_SUCCESS);
    594: }

    596: PetscErrorCode DMDestroyLabelLinkList_Internal(DM dm)
    597: {
    598:   DMLabelLink next = dm->labels;

    600:   PetscFunctionBegin;
    601:   /* destroy the labels */
    602:   while (next) {
    603:     DMLabelLink tmp = next->next;

    605:     if (next->label == dm->depthLabel) dm->depthLabel = NULL;
    606:     if (next->label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    607:     PetscCall(DMLabelDestroy(&next->label));
    608:     PetscCall(PetscFree(next));
    609:     next = tmp;
    610:   }
    611:   dm->labels = NULL;
    612:   PetscFunctionReturn(PETSC_SUCCESS);
    613: }

    615: PetscErrorCode DMDestroyCoordinates_Internal(DMCoordinates *c)
    616: {
    617:   PetscFunctionBegin;
    618:   c->dim = PETSC_DEFAULT;
    619:   PetscCall(DMDestroy(&c->dm));
    620:   PetscCall(VecDestroy(&c->x));
    621:   PetscCall(VecDestroy(&c->xl));
    622:   PetscCall(DMFieldDestroy(&c->field));
    623:   PetscFunctionReturn(PETSC_SUCCESS);
    624: }

    626: /*@
    627:   DMDestroy - Destroys a `DM`.

    629:   Collective

    631:   Input Parameter:
    632: . dm - the `DM` object to destroy

    634:   Level: developer

    636: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMType`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    637: @*/
    638: PetscErrorCode DMDestroy(DM *dm)
    639: {
    640:   PetscInt cnt;

    642:   PetscFunctionBegin;
    643:   if (!*dm) PetscFunctionReturn(PETSC_SUCCESS);

    646:   /* count all non-cyclic references in the doubly-linked list of coarse<->fine meshes */
    647:   PetscCall(DMCountNonCyclicReferences_Internal(*dm, PETSC_TRUE, PETSC_TRUE, &cnt));
    648:   --((PetscObject)*dm)->refct;
    649:   if (--cnt > 0) {
    650:     *dm = NULL;
    651:     PetscFunctionReturn(PETSC_SUCCESS);
    652:   }
    653:   if (((PetscObject)*dm)->refct < 0) PetscFunctionReturn(PETSC_SUCCESS);
    654:   ((PetscObject)*dm)->refct = 0;

    656:   PetscCall(DMClearGlobalVectors(*dm));
    657:   PetscCall(DMClearLocalVectors(*dm));
    658:   PetscCall(DMClearNamedGlobalVectors(*dm));
    659:   PetscCall(DMClearNamedLocalVectors(*dm));

    661:   /* Destroy the list of hooks */
    662:   {
    663:     DMCoarsenHookLink link, next;
    664:     for (link = (*dm)->coarsenhook; link; link = next) {
    665:       next = link->next;
    666:       PetscCall(PetscFree(link));
    667:     }
    668:     (*dm)->coarsenhook = NULL;
    669:   }
    670:   {
    671:     DMRefineHookLink link, next;
    672:     for (link = (*dm)->refinehook; link; link = next) {
    673:       next = link->next;
    674:       PetscCall(PetscFree(link));
    675:     }
    676:     (*dm)->refinehook = NULL;
    677:   }
    678:   {
    679:     DMSubDomainHookLink link, next;
    680:     for (link = (*dm)->subdomainhook; link; link = next) {
    681:       next = link->next;
    682:       PetscCall(PetscFree(link));
    683:     }
    684:     (*dm)->subdomainhook = NULL;
    685:   }
    686:   {
    687:     DMGlobalToLocalHookLink link, next;
    688:     for (link = (*dm)->gtolhook; link; link = next) {
    689:       next = link->next;
    690:       PetscCall(PetscFree(link));
    691:     }
    692:     (*dm)->gtolhook = NULL;
    693:   }
    694:   {
    695:     DMLocalToGlobalHookLink link, next;
    696:     for (link = (*dm)->ltoghook; link; link = next) {
    697:       next = link->next;
    698:       PetscCall(PetscFree(link));
    699:     }
    700:     (*dm)->ltoghook = NULL;
    701:   }
    702:   /* Destroy the work arrays */
    703:   {
    704:     DMWorkLink link, next;
    705:     PetscCheck(!(*dm)->workout, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Work array still checked out %p %p", (void *)(*dm)->workout, (*dm)->workout->mem);
    706:     for (link = (*dm)->workin; link; link = next) {
    707:       next = link->next;
    708:       PetscCall(PetscFree(link->mem));
    709:       PetscCall(PetscFree(link));
    710:     }
    711:     (*dm)->workin = NULL;
    712:   }
    713:   /* destroy the labels */
    714:   PetscCall(DMDestroyLabelLinkList_Internal(*dm));
    715:   /* destroy the fields */
    716:   PetscCall(DMClearFields(*dm));
    717:   /* destroy the boundaries */
    718:   {
    719:     DMBoundary next = (*dm)->boundary;
    720:     while (next) {
    721:       DMBoundary b = next;

    723:       next = b->next;
    724:       PetscCall(PetscFree(b));
    725:     }
    726:   }

    728:   PetscCall(PetscObjectDestroy(&(*dm)->dmksp));
    729:   PetscCall(PetscObjectDestroy(&(*dm)->dmsnes));
    730:   PetscCall(PetscObjectDestroy(&(*dm)->dmts));

    732:   if ((*dm)->ctx && (*dm)->ctxdestroy) PetscCall((*(*dm)->ctxdestroy)(&(*dm)->ctx));
    733:   PetscCall(MatFDColoringDestroy(&(*dm)->fd));
    734:   PetscCall(ISLocalToGlobalMappingDestroy(&(*dm)->ltogmap));
    735:   PetscCall(PetscFree((*dm)->vectype));
    736:   PetscCall(PetscFree((*dm)->mattype));

    738:   PetscCall(PetscSectionDestroy(&(*dm)->localSection));
    739:   PetscCall(PetscSectionDestroy(&(*dm)->globalSection));
    740:   PetscCall(PetscFree((*dm)->reorderSectionType));
    741:   PetscCall(PetscLayoutDestroy(&(*dm)->map));
    742:   PetscCall(PetscSectionDestroy(&(*dm)->defaultConstraint.section));
    743:   PetscCall(MatDestroy(&(*dm)->defaultConstraint.mat));
    744:   PetscCall(PetscSFDestroy(&(*dm)->sf));
    745:   PetscCall(PetscSFDestroy(&(*dm)->sectionSF));
    746:   PetscCall(PetscSFDestroy(&(*dm)->sfNatural));
    747:   PetscCall(PetscObjectDereference((PetscObject)(*dm)->sfMigration));
    748:   PetscCall(DMClearAuxiliaryVec(*dm));
    749:   PetscCall(PetscHMapAuxDestroy(&(*dm)->auxData));
    750:   if ((*dm)->coarseMesh && (*dm)->coarseMesh->fineMesh == *dm) PetscCall(DMSetFineDM((*dm)->coarseMesh, NULL));

    752:   PetscCall(DMDestroy(&(*dm)->coarseMesh));
    753:   if ((*dm)->fineMesh && (*dm)->fineMesh->coarseMesh == *dm) PetscCall(DMSetCoarseDM((*dm)->fineMesh, NULL));
    754:   PetscCall(DMDestroy(&(*dm)->fineMesh));
    755:   PetscCall(PetscFree((*dm)->Lstart));
    756:   PetscCall(PetscFree((*dm)->L));
    757:   PetscCall(PetscFree((*dm)->maxCell));
    758:   PetscCall(PetscFree2((*dm)->nullspaceConstructors, (*dm)->nearnullspaceConstructors));
    759:   PetscCall(DMDestroyCoordinates_Internal(&(*dm)->coordinates[0]));
    760:   PetscCall(DMDestroyCoordinates_Internal(&(*dm)->coordinates[1]));
    761:   if ((*dm)->transformDestroy) PetscCall((*(*dm)->transformDestroy)(*dm, (*dm)->transformCtx));
    762:   PetscCall(DMDestroy(&(*dm)->transformDM));
    763:   PetscCall(VecDestroy(&(*dm)->transform));
    764:   for (PetscInt i = 0; i < (*dm)->periodic.num_affines; i++) {
    765:     PetscCall(VecScatterDestroy(&(*dm)->periodic.affine_to_local[i]));
    766:     PetscCall(VecDestroy(&(*dm)->periodic.affine[i]));
    767:   }
    768:   if ((*dm)->periodic.num_affines > 0) PetscCall(PetscFree2((*dm)->periodic.affine_to_local, (*dm)->periodic.affine));

    770:   PetscCall(DMClearDS(*dm));
    771:   PetscCall(DMDestroy(&(*dm)->dmBC));
    772:   /* if memory was published with SAWs then destroy it */
    773:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*dm));

    775:   PetscTryTypeMethod(*dm, destroy);
    776:   PetscCall(DMMonitorCancel(*dm));
    777:   PetscCall(DMCeedDestroy(&(*dm)->dmceed));
    778: #ifdef PETSC_HAVE_LIBCEED
    779:   PetscCallCEED(CeedElemRestrictionDestroy(&(*dm)->ceedERestrict));
    780:   PetscCallCEED(CeedDestroy(&(*dm)->ceed));
    781: #endif
    782:   /* We do not destroy (*dm)->data here so that we can reference count backend objects */
    783:   PetscCall(PetscHeaderDestroy(dm));
    784:   PetscFunctionReturn(PETSC_SUCCESS);
    785: }

    787: /*@
    788:   DMSetUp - sets up the data structures inside a `DM` object

    790:   Collective

    792:   Input Parameter:
    793: . dm - the `DM` object to setup

    795:   Level: intermediate

    797:   Note:
    798:   This is usually called after various parameter setting operations and `DMSetFromOptions()` are called on the `DM`

    800: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    801: @*/
    802: PetscErrorCode DMSetUp(DM dm)
    803: {
    804:   PetscFunctionBegin;
    806:   if (dm->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
    807:   PetscTryTypeMethod(dm, setup);
    808:   dm->setupcalled = PETSC_TRUE;
    809:   PetscFunctionReturn(PETSC_SUCCESS);
    810: }

    812: /*@
    813:   DMSetFromOptions - sets parameters in a `DM` from the options database

    815:   Collective

    817:   Input Parameter:
    818: . dm - the `DM` object to set options for

    820:   Options Database Keys:
    821: + -dm_preallocate_only (true|false)                  - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros
    822: . -dm_vec_type type                                  - type of vector to create inside `DM`
    823: . -dm_mat_type type                                  - type of matrix to create inside `DM`
    824: . -dm_is_coloring_type (global|local)                - see `ISColoringType`
    825: . -dm_bind_below n                                   - bind (force execution on CPU) for `Vec` and `Mat` objects with local size (number of vector entries or matrix rows) below n; currently only supported for `DMDA`
    826: . -dm_plex_option_phases ph0_, ph1_, ...             - List of prefixes for option processing phases
    827: . -dm_plex_filename str                              - File containing a mesh
    828: . -dm_plex_boundary_filename str                     - File containing a mesh boundary
    829: . -dm_plex_name str                                  - Name of the mesh in the file
    830: . -dm_plex_shape shape                               - The domain shape, such as `BOX`, `SPHERE`, etc.
    831: . -dm_plex_cell ct                                   - Cell shape
    832: . -dm_plex_reference_cell_domain (true|false)        - Use a reference cell domain
    833: . -dm_plex_dim dim                                   - Set the topological dimension
    834: . -dm_plex_simplex (true|false)                      - `PETSC_TRUE` for simplex elements, `PETSC_FALSE` for tensor elements
    835: . -dm_plex_interpolate (true|false)                  - `PETSC_TRUE` turns on topological interpolation (creating edges and faces)
    836: . -dm_plex_orient (true|false)                       - `PETSC_TRUE` turns on topological orientation (flipping edges and faces)
    837: . -dm_plex_scale sc                                  - Scale factor for mesh coordinates
    838: . -dm_coord_remap (true|false)                       - Map coordinates using a function
    839: . -dm_plex_coordinate_dim dim                        - Change the coordinate dimension of a mesh (usually given with cdm_ prefix)
    840: . -dm_coord_map mapname                              - Select a builtin coordinate map
    841: . -dm_coord_map_params p0,p1,p2,...                  - Set coordinate mapping parameters
    842: . -dm_plex_box_faces m,n,p                           - Number of faces along each dimension
    843: . -dm_plex_box_lower x,y,z                           - Specify lower-left-bottom coordinates for the box
    844: . -dm_plex_box_upper x,y,z                           - Specify upper-right-top coordinates for the box
    845: . -dm_plex_box_bd bx,by,bz                           - Specify the `DMBoundaryType` for each direction
    846: . -dm_plex_sphere_radius r                           - The sphere radius
    847: . -dm_plex_ball_radius r                             - Radius of the ball
    848: . -dm_plex_cylinder_bd bz                            - Boundary type in the z direction
    849: . -dm_plex_cylinder_num_wedges n                     - Number of wedges around the cylinder
    850: . -dm_plex_reorder order                             - Reorder the mesh using the specified algorithm
    851: . -dm_refine_pre n                                   - The number of refinements before distribution
    852: . -dm_refine_uniform_pre (true|false)                - Flag for uniform refinement before distribution
    853: . -dm_refine_volume_limit_pre v                      - The maximum cell volume after refinement before distribution
    854: . -dm_refine n                                       - The number of refinements after distribution
    855: . -dm_extrude l                                      - Activate extrusion and specify the number of layers to extrude
    856: . -dm_plex_save_transform (true|false)               - Save the `DMPlexTransform` that produced this mesh
    857: . -dm_plex_transform_extrude_thickness t             - The total thickness of extruded layers
    858: . -dm_plex_transform_extrude_use_tensor (true|false) - Use tensor cells when extruding
    859: . -dm_plex_transform_extrude_symmetric (true|false)  - Extrude layers symmetrically about the surface
    860: . -dm_plex_transform_extrude_normal n0,...,nd        - Specify the extrusion direction
    861: . -dm_plex_transform_extrude_thicknesses t0,...,tl   - Specify thickness of each layer
    862: . -dm_plex_create_fv_ghost_cells                     - Flag to create finite volume ghost cells on the boundary
    863: . -dm_plex_fv_ghost_cells_label name                 - Label name for ghost cells boundary
    864: . -dm_distribute (true|false)                        - Flag to redistribute a mesh among processes
    865: . -dm_distribute_overlap n                           - The size of the overlap halo
    866: . -dm_plex_adj_cone (true|false)                     - Set adjacency direction
    867: . -dm_plex_adj_closure (true|false)                  - Set adjacency size
    868: . -dm_plex_use_ceed (true|false)                     - Use LibCEED as the FEM backend
    869: . -dm_plex_check_symmetry (true|false)               - Check that the adjacency information in the mesh is symmetric - `DMPlexCheckSymmetry()`
    870: . -dm_plex_check_skeleton (true|false)               - Check that each cell has the correct number of vertices (only for homogeneous simplex or tensor meshes) - `DMPlexCheckSkeleton()`
    871: . -dm_plex_check_faces (true|false)                  - Check that the faces of each cell give a vertex order this is consistent with what we expect from the cell type - `DMPlexCheckFaces()`
    872: . -dm_plex_check_geometry (true|false)               - Check that cells have positive volume - `DMPlexCheckGeometry()`
    873: . -dm_plex_check_pointsf (true|false)                - Check some necessary conditions for `PointSF` - `DMPlexCheckPointSF()`
    874: . -dm_plex_check_interface_cones (true|false)        - Check points on inter-partition interfaces have conforming order of cone points - `DMPlexCheckInterfaceCones()`
    875: - -dm_plex_check_all (true|false)                    - Perform all the checks above

    877:   Level: intermediate

    879:   Note:
    880:   For some `DMType` such as `DMDA` this cannot be called after `DMSetUp()` has been called.

    882: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    883:          `DMPlexCheckSymmetry()`, `DMPlexCheckSkeleton()`, `DMPlexCheckFaces()`, `DMPlexCheckGeometry()`, `DMPlexCheckPointSF()`, `DMPlexCheckInterfaceCones()`,
    884:          `DMSetOptionsPrefix()`, `DMType`, `DMPLEX`, `DMDA`, `DMSetUp()`
    885: @*/
    886: PetscErrorCode DMSetFromOptions(DM dm)
    887: {
    888:   char      typeName[256];
    889:   PetscBool flg;

    891:   PetscFunctionBegin;
    893:   dm->setfromoptionscalled = PETSC_TRUE;
    894:   if (dm->sf) PetscCall(PetscSFSetFromOptions(dm->sf));
    895:   if (dm->sectionSF) PetscCall(PetscSFSetFromOptions(dm->sectionSF));
    896:   if (dm->coordinates[0].dm) PetscCall(DMSetFromOptions(dm->coordinates[0].dm));
    897:   PetscObjectOptionsBegin((PetscObject)dm);
    898:   PetscCall(PetscOptionsBool("-dm_preallocate_only", "only preallocate matrix, but do not set column indices", "DMSetMatrixPreallocateOnly", dm->prealloc_only, &dm->prealloc_only, NULL));
    899:   PetscCall(PetscOptionsFList("-dm_vec_type", "Vector type used for created vectors", "DMSetVecType", VecList, dm->vectype, typeName, 256, &flg));
    900:   if (flg) PetscCall(DMSetVecType(dm, typeName));
    901:   PetscCall(PetscOptionsFList("-dm_mat_type", "Matrix type used for created matrices", "DMSetMatType", MatList, dm->mattype ? dm->mattype : typeName, typeName, sizeof(typeName), &flg));
    902:   if (flg) PetscCall(DMSetMatType(dm, typeName));
    903:   PetscCall(PetscOptionsEnum("-dm_blocking_type", "Topological point or field node blocking", "DMSetBlockingType", DMBlockingTypes, (PetscEnum)dm->blocking_type, (PetscEnum *)&dm->blocking_type, NULL));
    904:   PetscCall(PetscOptionsEnum("-dm_is_coloring_type", "Global or local coloring of Jacobian", "DMSetISColoringType", ISColoringTypes, (PetscEnum)dm->coloringtype, (PetscEnum *)&dm->coloringtype, NULL));
    905:   PetscCall(PetscOptionsInt("-dm_bind_below", "Set the size threshold (in entries) below which the Vec is bound to the CPU", "VecBindToCPU", dm->bind_below, &dm->bind_below, &flg));
    906:   PetscCall(PetscOptionsBool("-dm_ignore_perm_output", "Ignore the local section permutation on output", "DMGetOutputDM", dm->ignorePermOutput, &dm->ignorePermOutput, NULL));
    907:   PetscTryTypeMethod(dm, setfromoptions, PetscOptionsObject);
    908:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
    909:   PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)dm, PetscOptionsObject));
    910:   PetscOptionsEnd();
    911:   PetscFunctionReturn(PETSC_SUCCESS);
    912: }

    914: /*@
    915:   DMViewFromOptions - View a `DM` in a particular way based on a request in the options database

    917:   Collective

    919:   Input Parameters:
    920: + dm   - the `DM` object
    921: . obj  - optional object that provides the prefix for the options database (if `NULL` then the prefix in `obj` is used)
    922: - name - option string that is used to activate viewing

    924:   Options Database Key:
    925: . -name [viewertype][:...] - option name and values. See `PetscObjectViewFromOptions()` for the possible arguments

    927:   Level: intermediate

    929: .seealso: [](ch_dmbase), `DM`, `DMView()`, `PetscObjectViewFromOptions()`, `DMCreate()`
    930: @*/
    931: PetscErrorCode DMViewFromOptions(DM dm, PeOp PetscObject obj, const char name[])
    932: {
    933:   PetscFunctionBegin;
    935:   PetscCall(PetscObjectViewFromOptions((PetscObject)dm, obj, name));
    936:   PetscFunctionReturn(PETSC_SUCCESS);
    937: }

    939: /*@
    940:   DMView - Views a `DM`. Depending on the `PetscViewer` and its `PetscViewerFormat` it may print some ASCII information about the `DM` to the screen or a file or
    941:   save the `DM` in a binary file to be loaded later or create a visualization of the `DM`

    943:   Collective

    945:   Input Parameters:
    946: + dm - the `DM` object to view
    947: - v  - the viewer

    949:   Options Database Keys:
    950: + -view_pyvista_warp f                 - Warps the mesh by the active scalar with factor f
    951: . -view_pyvista_clip xl,xu,yl,yu,zl,zu - Defines the clipping box
    952: . -dm_view_draw_line_color color       - Specify the X-window color for cell borders
    953: . -dm_view_draw_cell_color color       - Specify the X-window color for cells
    954: - -dm_view_draw_affine (true|false)    - Flag to ignore high-order edges

    956:   Level: beginner

    958:   Notes:

    960:   `PetscViewer` = `PETSCVIEWERHDF5` i.e. HDF5 format can be used with `PETSC_VIEWER_HDF5_PETSC` as the `PetscViewerFormat` to save multiple `DMPLEX`
    961:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    962:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    964:   `PetscViewer` = `PETSCVIEWEREXODUSII` i.e. ExodusII format assumes that element blocks (mapped to "Cell sets" labels)
    965:   consists of sequentially numbered cells.

    967:   If `dm` has been distributed, only the part of the `DM` on MPI rank 0 (including "ghost" cells and vertices) will be written.

    969:   Only TRI, TET, QUAD, and HEX cells are supported in ExodusII.

    971:   `DMPLEX` only represents geometry while most post-processing software expect that a mesh also provides information on the discretization space. This function assumes that the file represents Lagrange finite elements of order 1 or 2.
    972:   The order of the mesh shall be set using `PetscViewerExodusIISetOrder()`

    974:   Variable names can be set and queried using `PetscViewerExodusII[Set/Get][Nodal/Zonal]VariableNames[s]`.

    976: .seealso: [](ch_dmbase), `DM`, `PetscViewer`, `PetscViewerFormat`, `PetscViewerSetFormat()`, `DMDestroy()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMLoad()`, `PetscObjectSetName()`
    977: @*/
    978: PetscErrorCode DMView(DM dm, PetscViewer v)
    979: {
    980:   PetscBool         isbinary;
    981:   PetscMPIInt       size;
    982:   PetscViewerFormat format;

    984:   PetscFunctionBegin;
    986:   if (!v) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)dm), &v));
    988:   /* Ideally, we would like to have this test on.
    989:      However, it currently breaks socket viz via GLVis.
    990:      During DMView(parallel_mesh,glvis_viewer), each
    991:      process opens a sequential ASCII socket to visualize
    992:      the local mesh, and PetscObjectView(dm,local_socket)
    993:      is internally called inside VecView_GLVis, incurring
    994:      in an error here */
    995:   /* PetscCheckSameComm(dm,1,v,2); */
    996:   PetscCall(PetscViewerCheckWritable(v));

    998:   PetscCall(PetscLogEventBegin(DM_View, v, 0, 0, 0));
    999:   PetscCall(PetscViewerGetFormat(v, &format));
    1000:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    1001:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);
    1002:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)dm, v));
    1003:   PetscCall(PetscObjectTypeCompare((PetscObject)v, PETSCVIEWERBINARY, &isbinary));
    1004:   if (isbinary) {
    1005:     PetscInt classid = DM_FILE_CLASSID;
    1006:     char     type[256];

    1008:     PetscCall(PetscViewerBinaryWrite(v, &classid, 1, PETSC_INT));
    1009:     PetscCall(PetscStrncpy(type, ((PetscObject)dm)->type_name, sizeof(type)));
    1010:     PetscCall(PetscViewerBinaryWrite(v, type, 256, PETSC_CHAR));
    1011:   }
    1012:   PetscTryTypeMethod(dm, view, v);
    1013:   PetscCall(PetscLogEventEnd(DM_View, v, 0, 0, 0));
    1014:   PetscFunctionReturn(PETSC_SUCCESS);
    1015: }

    1017: /*@
    1018:   DMCreateGlobalVector - Creates a global vector from a `DM` object. A global vector is a parallel vector that has no duplicate values shared between MPI ranks,
    1019:   that is it has no ghost locations.

    1021:   Collective

    1023:   Input Parameter:
    1024: . dm - the `DM` object

    1026:   Output Parameter:
    1027: . vec - the global vector

    1029:   Level: beginner

    1031:   Note:
    1032:   PETSc `Vec` always have all zero entries when created with `DMCreateGlobalVector()` until routines such as `VecSet()` or `VecSetValues()`
    1033:   are used to change the values. There is no reason to call `VecZeroEntries()` after creation.

    1035: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateLocalVector()`, `DMGetGlobalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1036:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1037: @*/
    1038: PetscErrorCode DMCreateGlobalVector(DM dm, Vec *vec)
    1039: {
    1040:   PetscFunctionBegin;
    1042:   PetscAssertPointer(vec, 2);
    1043:   PetscUseTypeMethod(dm, createglobalvector, vec);
    1044:   if (PetscDefined(USE_DEBUG)) {
    1045:     DM vdm;

    1047:     PetscCall(VecGetDM(*vec, &vdm));
    1048:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1049:   }
    1050:   PetscFunctionReturn(PETSC_SUCCESS);
    1051: }

    1053: /*@
    1054:   DMCreateLocalVector - Creates a local vector from a `DM` object.

    1056:   Not Collective

    1058:   Input Parameter:
    1059: . dm - the `DM` object

    1061:   Output Parameter:
    1062: . vec - the local vector

    1064:   Level: beginner

    1066:   Notes:
    1067:   A local vector usually has ghost locations that contain values that are owned by different MPI ranks. A global vector has no ghost locations.

    1069:   PETSc `Vec` always have all zero entries when created with `DMCreateLocalVector()` until routines such as `VecSet()` or `VecSetValues()`
    1070:   are used to change the values. There is no reason to call `VecZeroEntries()` after creation.

    1072: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateGlobalVector()`, `DMGetLocalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1073:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1074: @*/
    1075: PetscErrorCode DMCreateLocalVector(DM dm, Vec *vec)
    1076: {
    1077:   PetscFunctionBegin;
    1079:   PetscAssertPointer(vec, 2);
    1080:   PetscUseTypeMethod(dm, createlocalvector, vec);
    1081:   if (PetscDefined(USE_DEBUG)) {
    1082:     DM vdm;

    1084:     PetscCall(VecGetDM(*vec, &vdm));
    1085:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_LIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1086:   }
    1087:   PetscFunctionReturn(PETSC_SUCCESS);
    1088: }

    1090: /*@
    1091:   DMGetLocalToGlobalMapping - Accesses the local-to-global mapping in a `DM`.

    1093:   Collective

    1095:   Input Parameter:
    1096: . dm - the `DM` that provides the mapping

    1098:   Output Parameter:
    1099: . ltog - the mapping

    1101:   Level: advanced

    1103:   Notes:
    1104:   The global to local mapping allows one to set values into the global vector or matrix using `VecSetValuesLocal()` and `MatSetValuesLocal()`

    1106:   Vectors obtained with  `DMCreateGlobalVector()` and matrices obtained with `DMCreateMatrix()` already contain the global mapping so you do
    1107:   need to use this function with those objects.

    1109:   This mapping can then be used by `VecSetLocalToGlobalMapping()` or `MatSetLocalToGlobalMapping()`.

    1111: .seealso: [](ch_dmbase), `DM`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `VecSetLocalToGlobalMapping()`, `MatSetLocalToGlobalMapping()`,
    1112:           `DMCreateMatrix()`
    1113: @*/
    1114: PetscErrorCode DMGetLocalToGlobalMapping(DM dm, ISLocalToGlobalMapping *ltog)
    1115: {
    1116:   PetscInt bs = -1, bsLocal[2], bsMinMax[2];

    1118:   PetscFunctionBegin;
    1120:   PetscAssertPointer(ltog, 2);
    1121:   if (!dm->ltogmap) {
    1122:     PetscSection section, sectionGlobal;

    1124:     PetscCall(DMGetLocalSection(dm, &section));
    1125:     if (section) {
    1126:       const PetscInt *cdofs;
    1127:       PetscInt       *ltog;
    1128:       PetscInt        pStart, pEnd, n, p, k, l;

    1130:       PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1131:       PetscCall(PetscSectionGetChart(section, &pStart, &pEnd));
    1132:       PetscCall(PetscSectionGetStorageSize(section, &n));
    1133:       PetscCall(PetscMalloc1(n, &ltog)); /* We want the local+overlap size */
    1134:       for (p = pStart, l = 0; p < pEnd; ++p) {
    1135:         PetscInt bdof, cdof, dof, off, c, cind;

    1137:         /* Should probably use constrained dofs */
    1138:         PetscCall(PetscSectionGetDof(section, p, &dof));
    1139:         PetscCall(PetscSectionGetConstraintDof(section, p, &cdof));
    1140:         PetscCall(PetscSectionGetConstraintIndices(section, p, &cdofs));
    1141:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &off));
    1142:         /* If you have dofs, and constraints, and they are unequal, we set the blocksize to 1 */
    1143:         bdof = cdof && (dof - cdof) ? 1 : dof;
    1144:         if (dof) bs = bs < 0 ? bdof : PetscGCD(bs, bdof);

    1146:         for (c = 0, cind = 0; c < dof; ++c, ++l) {
    1147:           if (cind < cdof && c == cdofs[cind]) {
    1148:             ltog[l] = off < 0 ? off - c : -(off + c + 1);
    1149:             cind++;
    1150:           } else {
    1151:             ltog[l] = (off < 0 ? -(off + 1) : off) + c - cind;
    1152:           }
    1153:         }
    1154:       }
    1155:       /* Must have same blocksize on all procs (some might have no points) */
    1156:       bsLocal[0] = bs < 0 ? PETSC_INT_MAX : bs;
    1157:       bsLocal[1] = bs;
    1158:       PetscCall(PetscGlobalMinMaxInt(PetscObjectComm((PetscObject)dm), bsLocal, bsMinMax));
    1159:       if (bsMinMax[0] != bsMinMax[1]) {
    1160:         bs = 1;
    1161:       } else {
    1162:         bs = bsMinMax[0];
    1163:       }
    1164:       bs = bs < 0 ? 1 : bs;
    1165:       /* Must reduce indices by blocksize */
    1166:       if (bs > 1) {
    1167:         for (l = 0, k = 0; l < n; l += bs, ++k) {
    1168:           // Integer division of negative values truncates toward zero(!), not toward negative infinity
    1169:           ltog[k] = ltog[l] >= 0 ? ltog[l] / bs : -(-(ltog[l] + 1) / bs + 1);
    1170:         }
    1171:         n /= bs;
    1172:       }
    1173:       PetscCall(ISLocalToGlobalMappingCreate(PetscObjectComm((PetscObject)dm), bs, n, ltog, PETSC_OWN_POINTER, &dm->ltogmap));
    1174:     } else PetscUseTypeMethod(dm, getlocaltoglobalmapping);
    1175:   }
    1176:   *ltog = dm->ltogmap;
    1177:   PetscFunctionReturn(PETSC_SUCCESS);
    1178: }

    1180: /*@
    1181:   DMGetBlockSize - Gets the inherent block size associated with a `DM`

    1183:   Not Collective

    1185:   Input Parameter:
    1186: . dm - the `DM` with block structure

    1188:   Output Parameter:
    1189: . bs - the block size, 1 implies no exploitable block structure

    1191:   Level: intermediate

    1193:   Notes:
    1194:   This might be the number of degrees of freedom at each grid point for a structured grid.

    1196:   Complex `DM` that represent multiphysics or staggered grids or mixed-methods do not generally have a single inherent block size, but
    1197:   rather different locations in the vectors may have a different block size.

    1199: .seealso: [](ch_dmbase), `DM`, `ISCreateBlock()`, `VecSetBlockSize()`, `MatSetBlockSize()`, `DMGetLocalToGlobalMapping()`
    1200: @*/
    1201: PetscErrorCode DMGetBlockSize(DM dm, PetscInt *bs)
    1202: {
    1203:   PetscFunctionBegin;
    1205:   PetscAssertPointer(bs, 2);
    1206:   PetscCheck(dm->bs >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "DM does not have enough information to provide a block size yet");
    1207:   *bs = dm->bs;
    1208:   PetscFunctionReturn(PETSC_SUCCESS);
    1209: }

    1211: /*@
    1212:   DMCreateInterpolation - Gets the interpolation matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1213:   `DMCreateGlobalVector()` on the coarse `DM` to similar vectors on the fine grid `DM`.

    1215:   Collective

    1217:   Input Parameters:
    1218: + dmc - the `DM` object
    1219: - dmf - the second, finer `DM` object

    1221:   Output Parameters:
    1222: + mat - the interpolation
    1223: - vec - the scaling (optional, pass `NULL` if not needed), see `DMCreateInterpolationScale()`

    1225:   Level: developer

    1227:   Notes:
    1228:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1229:   DMCoarsen(). The coordinates set into the `DMDA` are completely ignored in computing the interpolation.

    1231:   For `DMDA` objects you can use this interpolation (more precisely the interpolation from the `DMGetCoordinateDM()`) to interpolate the mesh coordinate
    1232:   vectors EXCEPT in the periodic case where it does not make sense since the coordinate vectors are not periodic.

    1234: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolationScale()`
    1235: @*/
    1236: PetscErrorCode DMCreateInterpolation(DM dmc, DM dmf, Mat *mat, Vec *vec)
    1237: {
    1238:   PetscFunctionBegin;
    1241:   PetscAssertPointer(mat, 3);
    1242:   PetscCall(PetscLogEventBegin(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1243:   PetscUseTypeMethod(dmc, createinterpolation, dmf, mat, vec);
    1244:   PetscCall(PetscLogEventEnd(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1245:   PetscFunctionReturn(PETSC_SUCCESS);
    1246: }

    1248: /*@
    1249:   DMCreateInterpolationScale - Forms L = 1/(R*1) where 1 is the vector of all ones, and R is
    1250:   the transpose of the interpolation between the `DM`.

    1252:   Input Parameters:
    1253: + dac - `DM` that defines a coarse mesh
    1254: . daf - `DM` that defines a fine mesh
    1255: - mat - the restriction (or interpolation operator) from fine to coarse

    1257:   Output Parameter:
    1258: . scale - the scaled vector

    1260:   Level: advanced

    1262:   Note:
    1263:   xcoarse = diag(L)*R*xfine preserves scale and is thus suitable for state (versus residual)
    1264:   restriction. In other words xcoarse is the coarse representation of xfine.

    1266:   Developer Note:
    1267:   If the fine-scale `DMDA` has the -dm_bind_below option set to true, then `DMCreateInterpolationScale()` calls `MatSetBindingPropagates()`
    1268:   on the restriction/interpolation operator to set the bindingpropagates flag to true.

    1270: .seealso: [](ch_dmbase), `DM`, `MatRestrict()`, `MatInterpolate()`, `DMCreateInterpolation()`, `DMCreateRestriction()`, `DMCreateGlobalVector()`
    1271: @*/
    1272: PetscErrorCode DMCreateInterpolationScale(DM dac, DM daf, Mat mat, Vec *scale)
    1273: {
    1274:   Vec         fine;
    1275:   PetscScalar one = 1.0;
    1276: #if defined(PETSC_HAVE_CUDA)
    1277:   PetscBool bindingpropagates, isbound;
    1278: #endif

    1280:   PetscFunctionBegin;
    1281:   PetscCall(DMCreateGlobalVector(daf, &fine));
    1282:   PetscCall(DMCreateGlobalVector(dac, scale));
    1283:   PetscCall(VecSet(fine, one));
    1284: #if defined(PETSC_HAVE_CUDA)
    1285:   /* If the 'fine' Vec is bound to the CPU, it makes sense to bind 'mat' as well.
    1286:    * Note that we only do this for the CUDA case, right now, but if we add support for MatMultTranspose() via ViennaCL,
    1287:    * we'll need to do it for that case, too.*/
    1288:   PetscCall(VecGetBindingPropagates(fine, &bindingpropagates));
    1289:   if (bindingpropagates) {
    1290:     PetscCall(MatSetBindingPropagates(mat, PETSC_TRUE));
    1291:     PetscCall(VecBoundToCPU(fine, &isbound));
    1292:     PetscCall(MatBindToCPU(mat, isbound));
    1293:   }
    1294: #endif
    1295:   PetscCall(MatRestrict(mat, fine, *scale));
    1296:   PetscCall(VecDestroy(&fine));
    1297:   PetscCall(VecReciprocal(*scale));
    1298:   PetscFunctionReturn(PETSC_SUCCESS);
    1299: }

    1301: /*@
    1302:   DMCreateRestriction - Gets restriction matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1303:   `DMCreateGlobalVector()` on the fine `DM` to similar vectors on the coarse grid `DM`.

    1305:   Collective

    1307:   Input Parameters:
    1308: + dmc - the `DM` object
    1309: - dmf - the second, finer `DM` object

    1311:   Output Parameter:
    1312: . mat - the restriction

    1314:   Level: developer

    1316:   Note:
    1317:   This only works for `DMSTAG`. For many situations either the transpose of the operator obtained with `DMCreateInterpolation()` or that
    1318:   matrix multiplied by the vector obtained with `DMCreateInterpolationScale()` provides the desired object.

    1320: .seealso: [](ch_dmbase), `DM`, `DMRestrict()`, `DMInterpolate()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateInterpolation()`
    1321: @*/
    1322: PetscErrorCode DMCreateRestriction(DM dmc, DM dmf, Mat *mat)
    1323: {
    1324:   PetscFunctionBegin;
    1327:   PetscAssertPointer(mat, 3);
    1328:   PetscCall(PetscLogEventBegin(DM_CreateRestriction, dmc, dmf, 0, 0));
    1329:   PetscUseTypeMethod(dmc, createrestriction, dmf, mat);
    1330:   PetscCall(PetscLogEventEnd(DM_CreateRestriction, dmc, dmf, 0, 0));
    1331:   PetscFunctionReturn(PETSC_SUCCESS);
    1332: }

    1334: /*@
    1335:   DMCreateInjection - Gets injection matrix between two `DM` objects.

    1337:   Collective

    1339:   Input Parameters:
    1340: + dac - the `DM` object
    1341: - daf - the second, finer `DM` object

    1343:   Output Parameter:
    1344: . mat - the injection

    1346:   Level: developer

    1348:   Notes:
    1349:   This is an operator that applied to a vector obtained with `DMCreateGlobalVector()` on the
    1350:   fine grid maps the values to a vector on the vector on the coarse `DM` by simply selecting
    1351:   the values on the coarse grid points. This compares to the operator obtained by
    1352:   `DMCreateRestriction()` or the transpose of the operator obtained by
    1353:   `DMCreateInterpolation()` that uses a "local weighted average" of the values around the
    1354:   coarse grid point as the coarse grid value.

    1356:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1357:   `DMCoarsen()`. The coordinates set into the `DMDA` are completely ignored in computing the injection.

    1359: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateInterpolation()`,
    1360:           `DMCreateRestriction()`, `MatRestrict()`, `MatInterpolate()`
    1361: @*/
    1362: PetscErrorCode DMCreateInjection(DM dac, DM daf, Mat *mat)
    1363: {
    1364:   PetscFunctionBegin;
    1367:   PetscAssertPointer(mat, 3);
    1368:   PetscCall(PetscLogEventBegin(DM_CreateInjection, dac, daf, 0, 0));
    1369:   PetscUseTypeMethod(dac, createinjection, daf, mat);
    1370:   PetscCall(PetscLogEventEnd(DM_CreateInjection, dac, daf, 0, 0));
    1371:   PetscFunctionReturn(PETSC_SUCCESS);
    1372: }

    1374: /*@
    1375:   DMCreateMassMatrix - Gets the mass matrix between two `DM` objects, M_ij = \int \phi_i \psi_j where the \phi are Galerkin basis functions for a
    1376:   a Galerkin finite element model on the `DM`

    1378:   Collective

    1380:   Input Parameters:
    1381: + dmc - the target `DM` object
    1382: - dmf - the source `DM` object, can be `NULL`

    1384:   Output Parameter:
    1385: . mat - the mass matrix

    1387:   Level: developer

    1389:   Notes:
    1390:   For `DMPLEX` the finite element model for the `DM` must have been already provided.

    1392:   if `dmc` is `dmf` or `NULL`, then x^t M x is an approximation to the L2 norm of the vector x which is obtained by `DMCreateGlobalVector()`

    1394: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrixLumped()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1395: @*/
    1396: PetscErrorCode DMCreateMassMatrix(DM dmc, DM dmf, Mat *mat)
    1397: {
    1398:   PetscFunctionBegin;
    1400:   if (!dmf) dmf = dmc;
    1402:   PetscAssertPointer(mat, 3);
    1403:   PetscCall(PetscLogEventBegin(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1404:   PetscUseTypeMethod(dmc, createmassmatrix, dmf, mat);
    1405:   PetscCall(PetscLogEventEnd(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1406:   PetscFunctionReturn(PETSC_SUCCESS);
    1407: }

    1409: /*@
    1410:   DMCreateMassMatrixLumped - Gets the lumped mass matrix for a given `DM`

    1412:   Collective

    1414:   Input Parameter:
    1415: . dm - the `DM` object

    1417:   Output Parameters:
    1418: + llm - the local lumped mass matrix, which is a diagonal matrix, represented as a vector
    1419: - lm  - the global lumped mass matrix, which is a diagonal matrix, represented as a vector

    1421:   Level: developer

    1423:   Note:
    1424:   See `DMCreateMassMatrix()` for how to create the non-lumped version of the mass matrix.

    1426: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1427: @*/
    1428: PetscErrorCode DMCreateMassMatrixLumped(DM dm, Vec *llm, Vec *lm)
    1429: {
    1430:   PetscFunctionBegin;
    1432:   if (llm) PetscAssertPointer(llm, 2);
    1433:   if (lm) PetscAssertPointer(lm, 3);
    1434:   if (llm || lm) PetscUseTypeMethod(dm, createmassmatrixlumped, llm, lm);
    1435:   PetscFunctionReturn(PETSC_SUCCESS);
    1436: }

    1438: /*@
    1439:   DMCreateGradientMatrix - Gets the gradient matrix between two `DM` objects, M_(ic)j = \int \partial_c \phi_i \psi_j where the \phi are Galerkin basis functions for a Galerkin finite element model on the `DM`

    1441:   Collective

    1443:   Input Parameters:
    1444: + dmc - the target `DM` object
    1445: - dmf - the source `DM` object, can be `NULL`

    1447:   Output Parameter:
    1448: . mat - the gradient matrix

    1450:   Level: developer

    1452:   Notes:
    1453:   For `DMPLEX` the finite element model for the `DM` must have been already provided.

    1455: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMassMatrixLumped()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1456: @*/
    1457: PetscErrorCode DMCreateGradientMatrix(DM dmc, DM dmf, Mat *mat)
    1458: {
    1459:   PetscFunctionBegin;
    1461:   if (!dmf) dmf = dmc;
    1463:   PetscAssertPointer(mat, 3);
    1464:   PetscUseTypeMethod(dmc, creategradientmatrix, dmf, mat);
    1465:   PetscFunctionReturn(PETSC_SUCCESS);
    1466: }

    1468: /*@
    1469:   DMCreateColoring - Gets coloring of a graph associated with the `DM`. Often the graph represents the operator matrix associated with the discretization
    1470:   of a PDE on the `DM`.

    1472:   Collective

    1474:   Input Parameters:
    1475: + dm    - the `DM` object
    1476: - ctype - `IS_COLORING_LOCAL` or `IS_COLORING_GLOBAL`

    1478:   Output Parameter:
    1479: . coloring - the coloring

    1481:   Level: developer

    1483:   Notes:
    1484:   Coloring of matrices can also be computed directly from the sparse matrix nonzero structure via the `MatColoring` object or from the mesh from which the
    1485:   matrix comes from (what this function provides). In general using the mesh produces a more optimal coloring (fewer colors).

    1487:   This produces a coloring with the distance of 2, see `MatSetColoringDistance()` which can be used for efficiently computing Jacobians with `MatFDColoringCreate()`
    1488:   For `DMDA` in three dimensions with periodic boundary conditions the number of grid points in each dimension must be divisible by 2*stencil_width + 1,
    1489:   otherwise an error will be generated.

    1491: .seealso: [](ch_dmbase), `DM`, `ISColoring`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatType()`, `MatColoring`, `MatFDColoringCreate()`
    1492: @*/
    1493: PetscErrorCode DMCreateColoring(DM dm, ISColoringType ctype, ISColoring *coloring)
    1494: {
    1495:   PetscFunctionBegin;
    1497:   PetscAssertPointer(coloring, 3);
    1498:   PetscUseTypeMethod(dm, getcoloring, ctype, coloring);
    1499:   PetscFunctionReturn(PETSC_SUCCESS);
    1500: }

    1502: /*@
    1503:   DMCreateMatrix - Gets an empty matrix for a `DM` that is most commonly used to store the Jacobian of a discrete PDE operator.

    1505:   Collective

    1507:   Input Parameter:
    1508: . dm - the `DM` object

    1510:   Output Parameter:
    1511: . mat - the empty Jacobian

    1513:   Options Database Key:
    1514: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros

    1516:   Level: beginner

    1518:   Notes:
    1519:   This properly preallocates the number of nonzeros in the sparse matrix so you
    1520:   do not need to do it yourself.

    1522:   By default it also sets the nonzero structure and puts in the zero entries. To prevent setting
    1523:   the nonzero pattern call `DMSetMatrixPreallocateOnly()`

    1525:   For `DMDA`, when you call `MatView()` on this matrix it is displayed using the global natural ordering, NOT in the ordering used
    1526:   internally by PETSc.

    1528:   For `DMDA`, in general it is easiest to use `MatSetValuesStencil()` or `MatSetValuesLocal()` to put values into the matrix because
    1529:   `MatSetValues()` requires the indices for the global numbering for the `DMDA` which is complic`ated to compute

    1531: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMSetMatType()`, `DMCreateMassMatrix()`
    1532: @*/
    1533: PetscErrorCode DMCreateMatrix(DM dm, Mat *mat)
    1534: {
    1535:   PetscFunctionBegin;
    1537:   PetscAssertPointer(mat, 2);
    1538:   PetscCall(MatInitializePackage());
    1539:   PetscCall(PetscLogEventBegin(DM_CreateMatrix, 0, 0, 0, 0));
    1540:   PetscUseTypeMethod(dm, creatematrix, mat);
    1541:   if (PetscDefined(USE_DEBUG)) {
    1542:     DM mdm;

    1544:     PetscCall(MatGetDM(*mat, &mdm));
    1545:     PetscCheck(mdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the matrix", ((PetscObject)dm)->type_name);
    1546:   }
    1547:   /* Handle nullspace and near nullspace */
    1548:   if (dm->Nf) {
    1549:     MatNullSpace nullSpace;
    1550:     PetscInt     Nf, f;

    1552:     PetscCall(DMGetNumFields(dm, &Nf));
    1553:     for (f = 0; f < Nf; ++f) {
    1554:       if (dm->nullspaceConstructors && dm->nullspaceConstructors[f]) {
    1555:         PetscCall((*dm->nullspaceConstructors[f])(dm, f, f, &nullSpace));
    1556:         PetscCall(MatSetNullSpace(*mat, nullSpace));
    1557:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1558:         break;
    1559:       }
    1560:     }
    1561:     for (f = 0; f < Nf; ++f) {
    1562:       if (dm->nearnullspaceConstructors && dm->nearnullspaceConstructors[f]) {
    1563:         PetscCall((*dm->nearnullspaceConstructors[f])(dm, f, f, &nullSpace));
    1564:         PetscCall(MatSetNearNullSpace(*mat, nullSpace));
    1565:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1566:       }
    1567:     }
    1568:   }
    1569:   PetscCall(PetscLogEventEnd(DM_CreateMatrix, 0, 0, 0, 0));
    1570:   PetscFunctionReturn(PETSC_SUCCESS);
    1571: }

    1573: /*@
    1574:   DMSetMatrixPreallocateSkip - When `DMCreateMatrix()` is called the matrix sizes and
    1575:   `ISLocalToGlobalMapping` will be properly set, but the data structures to store values in the
    1576:   matrices will not be preallocated.

    1578:   Logically Collective

    1580:   Input Parameters:
    1581: + dm   - the `DM`
    1582: - skip - `PETSC_TRUE` to skip preallocation

    1584:   Level: developer

    1586:   Note:
    1587:   This is most useful to reduce initialization costs when `MatSetPreallocationCOO()` and
    1588:   `MatSetValuesCOO()` will be used.

    1590: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateOnly()`
    1591: @*/
    1592: PetscErrorCode DMSetMatrixPreallocateSkip(DM dm, PetscBool skip)
    1593: {
    1594:   PetscFunctionBegin;
    1596:   dm->prealloc_skip = skip;
    1597:   PetscFunctionReturn(PETSC_SUCCESS);
    1598: }

    1600: /*@
    1601:   DMSetMatrixPreallocateOnly - When `DMCreateMatrix()` is called the matrix will be properly
    1602:   preallocated but the nonzero structure and zero values will not be set.

    1604:   Logically Collective

    1606:   Input Parameters:
    1607: + dm   - the `DM`
    1608: - only - `PETSC_TRUE` if only want preallocation

    1610:   Options Database Key:
    1611: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()`, `DMCreateMassMatrix()`, but do not fill it with zeros

    1613:   Level: developer

    1615: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateSkip()`
    1616: @*/
    1617: PetscErrorCode DMSetMatrixPreallocateOnly(DM dm, PetscBool only)
    1618: {
    1619:   PetscFunctionBegin;
    1621:   dm->prealloc_only = only;
    1622:   PetscFunctionReturn(PETSC_SUCCESS);
    1623: }

    1625: /*@
    1626:   DMSetMatrixStructureOnly - When `DMCreateMatrix()` is called, the matrix nonzero structure will be created
    1627:   but the array for numerical values will not be allocated.

    1629:   Logically Collective

    1631:   Input Parameters:
    1632: + dm   - the `DM`
    1633: - only - `PETSC_TRUE` if you only want matrix nonzero structure

    1635:   Level: developer

    1637: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMSetMatrixPreallocateSkip()`
    1638: @*/
    1639: PetscErrorCode DMSetMatrixStructureOnly(DM dm, PetscBool only)
    1640: {
    1641:   PetscFunctionBegin;
    1643:   dm->structure_only = only;
    1644:   PetscFunctionReturn(PETSC_SUCCESS);
    1645: }

    1647: /*@
    1648:   DMSetBlockingType - set the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1650:   Logically Collective

    1652:   Input Parameters:
    1653: + dm    - the `DM`
    1654: - btype - block by topological point or field node

    1656:   Options Database Key:
    1657: . -dm_blocking_type (topological_point|field_node) - use topological point blocking or field node blocking

    1659:   Level: advanced

    1661: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1662: @*/
    1663: PetscErrorCode DMSetBlockingType(DM dm, DMBlockingType btype)
    1664: {
    1665:   PetscFunctionBegin;
    1667:   dm->blocking_type = btype;
    1668:   PetscFunctionReturn(PETSC_SUCCESS);
    1669: }

    1671: /*@
    1672:   DMGetBlockingType - get the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1674:   Not Collective

    1676:   Input Parameter:
    1677: . dm - the `DM`

    1679:   Output Parameter:
    1680: . btype - block by topological point or field node

    1682:   Level: advanced

    1684: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1685: @*/
    1686: PetscErrorCode DMGetBlockingType(DM dm, DMBlockingType *btype)
    1687: {
    1688:   PetscFunctionBegin;
    1690:   PetscAssertPointer(btype, 2);
    1691:   *btype = dm->blocking_type;
    1692:   PetscFunctionReturn(PETSC_SUCCESS);
    1693: }

    1695: /*@C
    1696:   DMGetWorkArray - Gets a work array guaranteed to be at least the input size, restore with `DMRestoreWorkArray()`

    1698:   Not Collective

    1700:   Input Parameters:
    1701: + dm    - the `DM` object
    1702: . count - The minimum size
    1703: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, or `MPIU_INT`)

    1705:   Output Parameter:
    1706: . mem - the work array

    1708:   Level: developer

    1710:   Notes:
    1711:   A `DM` may stash the array between instantiations so using this routine may be more efficient than calling `PetscMalloc()`

    1713:   The array may contain nonzero values

    1715: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMRestoreWorkArray()`, `PetscMalloc()`
    1716: @*/
    1717: PetscErrorCode DMGetWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1718: {
    1719:   DMWorkLink  link;
    1720:   PetscMPIInt dsize;

    1722:   PetscFunctionBegin;
    1724:   PetscAssertPointer(mem, 4);
    1725:   if (!count) {
    1726:     *(void **)mem = NULL;
    1727:     PetscFunctionReturn(PETSC_SUCCESS);
    1728:   }
    1729:   if (dm->workin) {
    1730:     link       = dm->workin;
    1731:     dm->workin = dm->workin->next;
    1732:   } else {
    1733:     PetscCall(PetscNew(&link));
    1734:   }
    1735:   /* Avoid MPI_Type_size for most used datatypes
    1736:      Get size directly */
    1737:   if (dtype == MPIU_INT) dsize = sizeof(PetscInt);
    1738:   else if (dtype == MPIU_REAL) dsize = sizeof(PetscReal);
    1739: #if defined(PETSC_USE_64BIT_INDICES)
    1740:   else if (dtype == MPI_INT) dsize = sizeof(int);
    1741: #endif
    1742: #if defined(PETSC_USE_COMPLEX)
    1743:   else if (dtype == MPIU_SCALAR) dsize = sizeof(PetscScalar);
    1744: #endif
    1745:   else PetscCallMPI(MPI_Type_size(dtype, &dsize));

    1747:   if (((size_t)dsize * count) > link->bytes) {
    1748:     PetscCall(PetscFree(link->mem));
    1749:     PetscCall(PetscMalloc(dsize * count, &link->mem));
    1750:     link->bytes = dsize * count;
    1751:   }
    1752:   link->next    = dm->workout;
    1753:   dm->workout   = link;
    1754:   *(void **)mem = link->mem;
    1755:   PetscFunctionReturn(PETSC_SUCCESS);
    1756: }

    1758: /*@C
    1759:   DMRestoreWorkArray - Restores a work array obtained with `DMCreateWorkArray()`

    1761:   Not Collective

    1763:   Input Parameters:
    1764: + dm    - the `DM` object
    1765: . count - The minimum size
    1766: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_INT`

    1768:   Output Parameter:
    1769: . mem - the work array

    1771:   Level: developer

    1773:   Developer Note:
    1774:   count and dtype are ignored, they are only needed for `DMGetWorkArray()`

    1776: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMGetWorkArray()`
    1777: @*/
    1778: PetscErrorCode DMRestoreWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1779: {
    1780:   DMWorkLink *p, link;

    1782:   PetscFunctionBegin;
    1783:   PetscAssertPointer(mem, 4);
    1784:   (void)count;
    1785:   (void)dtype;
    1786:   if (!*(void **)mem) PetscFunctionReturn(PETSC_SUCCESS);
    1787:   for (p = &dm->workout; (link = *p); p = &link->next) {
    1788:     if (link->mem == *(void **)mem) {
    1789:       *p            = link->next;
    1790:       link->next    = dm->workin;
    1791:       dm->workin    = link;
    1792:       *(void **)mem = NULL;
    1793:       PetscFunctionReturn(PETSC_SUCCESS);
    1794:     }
    1795:   }
    1796:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Array was not checked out");
    1797: }

    1799: /*@C
    1800:   DMSetNullSpaceConstructor - Provide a callback function which constructs the nullspace for a given field, defined with `DMAddField()`, when function spaces
    1801:   are joined or split, such as in `DMCreateSubDM()`

    1803:   Logically Collective; No Fortran Support

    1805:   Input Parameters:
    1806: + dm     - The `DM`
    1807: . field  - The field number for the nullspace
    1808: - nullsp - A callback to create the nullspace

    1810:   Calling sequence of `nullsp`:
    1811: + dm        - The present `DM`
    1812: . origField - The field number given above, in the original `DM`
    1813: . field     - The field number in dm
    1814: - nullSpace - The nullspace for the given field

    1816:   Level: intermediate

    1818: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1819: @*/
    1820: PetscErrorCode DMSetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1821: {
    1822:   PetscFunctionBegin;
    1824:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1825:   PetscCheck(dm->nullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1826:   dm->nullspaceConstructors[field] = nullsp;
    1827:   PetscFunctionReturn(PETSC_SUCCESS);
    1828: }

    1830: /*@C
    1831:   DMGetNullSpaceConstructor - Return the callback function which constructs the nullspace for a given field, defined with `DMAddField()`

    1833:   Not Collective; No Fortran Support

    1835:   Input Parameters:
    1836: + dm    - The `DM`
    1837: - field - The field number for the nullspace

    1839:   Output Parameter:
    1840: . nullsp - A callback to create the nullspace

    1842:   Calling sequence of `nullsp`:
    1843: + dm        - The present DM
    1844: . origField - The field number given above, in the original DM
    1845: . field     - The field number in dm
    1846: - nullSpace - The nullspace for the given field

    1848:   Level: intermediate

    1850: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1851: @*/
    1852: PetscErrorCode DMGetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1853: {
    1854:   PetscFunctionBegin;
    1856:   PetscAssertPointer(nullsp, 3);
    1857:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1858:   PetscCheck(dm->nullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1859:   *nullsp = dm->nullspaceConstructors[field];
    1860:   PetscFunctionReturn(PETSC_SUCCESS);
    1861: }

    1863: /*@C
    1864:   DMSetNearNullSpaceConstructor - Provide a callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1866:   Logically Collective; No Fortran Support

    1868:   Input Parameters:
    1869: + dm     - The `DM`
    1870: . field  - The field number for the nullspace
    1871: - nullsp - A callback to create the near-nullspace

    1873:   Calling sequence of `nullsp`:
    1874: + dm        - The present `DM`
    1875: . origField - The field number given above, in the original `DM`
    1876: . field     - The field number in dm
    1877: - nullSpace - The nullspace for the given field

    1879:   Level: intermediate

    1881: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`,
    1882:           `MatNullSpace`
    1883: @*/
    1884: PetscErrorCode DMSetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1885: {
    1886:   PetscFunctionBegin;
    1888:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1889:   PetscCheck(dm->nearnullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1890:   dm->nearnullspaceConstructors[field] = nullsp;
    1891:   PetscFunctionReturn(PETSC_SUCCESS);
    1892: }

    1894: /*@C
    1895:   DMGetNearNullSpaceConstructor - Return the callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1897:   Not Collective; No Fortran Support

    1899:   Input Parameters:
    1900: + dm    - The `DM`
    1901: - field - The field number for the nullspace

    1903:   Output Parameter:
    1904: . nullsp - A callback to create the near-nullspace

    1906:   Calling sequence of `nullsp`:
    1907: + dm        - The present `DM`
    1908: . origField - The field number given above, in the original `DM`
    1909: . field     - The field number in dm
    1910: - nullSpace - The nullspace for the given field

    1912:   Level: intermediate

    1914: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`,
    1915:           `MatNullSpace`, `DMCreateSuperDM()`
    1916: @*/
    1917: PetscErrorCode DMGetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1918: {
    1919:   PetscFunctionBegin;
    1921:   PetscAssertPointer(nullsp, 3);
    1922:   PetscCheck(field < dm->Nf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= %" PetscInt_FMT " fields", field, dm->Nf);
    1923:   PetscCheck(dm->nearnullspaceConstructors, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Must call DMCreateDS() to setup nullspaces");
    1924:   *nullsp = dm->nearnullspaceConstructors[field];
    1925:   PetscFunctionReturn(PETSC_SUCCESS);
    1926: }

    1928: /*@C
    1929:   DMCreateFieldIS - Creates a set of `IS` objects with the global indices of dofs for each field defined with `DMAddField()`

    1931:   Not Collective; No Fortran Support

    1933:   Input Parameter:
    1934: . dm - the `DM` object

    1936:   Output Parameters:
    1937: + numFields  - The number of fields (or `NULL` if not requested)
    1938: . fieldNames - The name of each field (or `NULL` if not requested)
    1939: - fields     - The global indices for each field (or `NULL` if not requested)

    1941:   Level: intermediate

    1943:   Note:
    1944:   The user is responsible for freeing all requested arrays. In particular, every entry of `fieldNames` should be freed with
    1945:   `PetscFree()`, every entry of `fields` should be destroyed with `ISDestroy()`, and both arrays should be freed with
    1946:   `PetscFree()`.

    1948:   Developer Note:
    1949:   It is not clear why both this function and `DMCreateFieldDecomposition()` exist. Having two seems redundant and confusing. This function should
    1950:   likely be removed.

    1952: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1953:           `DMCreateFieldDecomposition()`
    1954: @*/
    1955: PetscErrorCode DMCreateFieldIS(DM dm, PetscInt *numFields, char ***fieldNames, IS *fields[])
    1956: {
    1957:   PetscSection section, sectionGlobal;

    1959:   PetscFunctionBegin;
    1961:   if (numFields) {
    1962:     PetscAssertPointer(numFields, 2);
    1963:     *numFields = 0;
    1964:   }
    1965:   if (fieldNames) {
    1966:     PetscAssertPointer(fieldNames, 3);
    1967:     *fieldNames = NULL;
    1968:   }
    1969:   if (fields) {
    1970:     PetscAssertPointer(fields, 4);
    1971:     *fields = NULL;
    1972:   }
    1973:   PetscCall(DMGetLocalSection(dm, &section));
    1974:   if (section) {
    1975:     PetscInt *fieldSizes, *fieldNc, **fieldIndices;
    1976:     PetscInt  nF, f, pStart, pEnd, p;

    1978:     PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1979:     PetscCall(PetscSectionGetNumFields(section, &nF));
    1980:     PetscCall(PetscMalloc3(nF, &fieldSizes, nF, &fieldNc, nF, &fieldIndices));
    1981:     PetscCall(PetscSectionGetChart(sectionGlobal, &pStart, &pEnd));
    1982:     for (f = 0; f < nF; ++f) {
    1983:       fieldSizes[f] = 0;
    1984:       PetscCall(PetscSectionGetFieldComponents(section, f, &fieldNc[f]));
    1985:     }
    1986:     for (p = pStart; p < pEnd; ++p) {
    1987:       PetscInt gdof;

    1989:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    1990:       if (gdof > 0) {
    1991:         for (f = 0; f < nF; ++f) {
    1992:           PetscInt fdof, fcdof, fpdof;

    1994:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    1995:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    1996:           fpdof = fdof - fcdof;
    1997:           if (fpdof && fpdof != fieldNc[f]) {
    1998:             /* Layout does not admit a pointwise block size */
    1999:             fieldNc[f] = 1;
    2000:           }
    2001:           fieldSizes[f] += fpdof;
    2002:         }
    2003:       }
    2004:     }
    2005:     for (f = 0; f < nF; ++f) {
    2006:       PetscCall(PetscMalloc1(fieldSizes[f], &fieldIndices[f]));
    2007:       fieldSizes[f] = 0;
    2008:     }
    2009:     for (p = pStart; p < pEnd; ++p) {
    2010:       PetscInt gdof, goff;

    2012:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    2013:       if (gdof > 0) {
    2014:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &goff));
    2015:         for (f = 0; f < nF; ++f) {
    2016:           PetscInt fdof, fcdof, fc;

    2018:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    2019:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    2020:           for (fc = 0; fc < fdof - fcdof; ++fc, ++fieldSizes[f]) fieldIndices[f][fieldSizes[f]] = goff++;
    2021:         }
    2022:       }
    2023:     }
    2024:     if (numFields) *numFields = nF;
    2025:     if (fieldNames) {
    2026:       PetscCall(PetscMalloc1(nF, fieldNames));
    2027:       for (f = 0; f < nF; ++f) {
    2028:         const char *fieldName;

    2030:         PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    2031:         PetscCall(PetscStrallocpy(fieldName, &(*fieldNames)[f]));
    2032:       }
    2033:     }
    2034:     if (fields) {
    2035:       PetscCall(PetscMalloc1(nF, fields));
    2036:       for (f = 0; f < nF; ++f) {
    2037:         PetscInt bs, in[2], out[2];

    2039:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), fieldSizes[f], fieldIndices[f], PETSC_OWN_POINTER, &(*fields)[f]));
    2040:         in[0] = -fieldNc[f];
    2041:         in[1] = fieldNc[f];
    2042:         PetscCallMPI(MPIU_Allreduce(in, out, 2, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    2043:         bs = (-out[0] == out[1]) ? out[1] : 1;
    2044:         PetscCall(ISSetBlockSize((*fields)[f], bs));
    2045:       }
    2046:     }
    2047:     PetscCall(PetscFree3(fieldSizes, fieldNc, fieldIndices));
    2048:   } else PetscTryTypeMethod(dm, createfieldis, numFields, fieldNames, fields);
    2049:   PetscFunctionReturn(PETSC_SUCCESS);
    2050: }

    2052: /*@C
    2053:   DMCreateFieldDecomposition - Returns a list of `IS` objects defining a decomposition of a problem into subproblems
    2054:   corresponding to different fields.

    2056:   Not Collective; No Fortran Support

    2058:   Input Parameter:
    2059: . dm - the `DM` object

    2061:   Output Parameters:
    2062: + len      - The number of fields (or `NULL` if not requested)
    2063: . namelist - The name for each field (or `NULL` if not requested)
    2064: . islist   - The global indices for each field (or `NULL` if not requested)
    2065: - dmlist   - The `DM`s for each field subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2067:   Level: intermediate

    2069:   Notes:
    2070:   Each `IS` contains the global indices of the dofs of the corresponding field, defined by
    2071:   `DMAddField()`. The optional list of `DM`s define the `DM` for each subproblem.

    2073:   The same as `DMCreateFieldIS()` but also returns a `DM` for each field.

    2075:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2076:   `PetscFree()`, every entry of `islist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2077:   and all of the arrays should be freed with `PetscFree()`.

    2079:   Fortran Notes:
    2080:   Use the declarations
    2081: .vb
    2082:   character(80), pointer :: namelist(:)
    2083:   IS, pointer :: islist(:)
    2084:   DM, pointer :: dmlist(:)
    2085: .ve

    2087:   `namelist` must be provided, `islist` may be `PETSC_NULL_IS_POINTER` and `dmlist` may be `PETSC_NULL_DM_POINTER`

    2089:   Use `DMDestroyFieldDecomposition()` to free the returned objects

    2091:   Developer Notes:
    2092:   It is not clear why this function and `DMCreateFieldIS()` exist. Having two seems redundant and confusing.

    2094:   Unlike  `DMRefine()`, `DMCoarsen()`, and `DMCreateDomainDecomposition()` this provides no mechanism to provide hooks that are called after the
    2095:   decomposition is computed.

    2097: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMCreateFieldIS()`, `DMCreateSubDM()`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2098: @*/
    2099: PetscErrorCode DMCreateFieldDecomposition(DM dm, PetscInt *len, char ***namelist, IS *islist[], DM *dmlist[])
    2100: {
    2101:   PetscFunctionBegin;
    2103:   if (len) {
    2104:     PetscAssertPointer(len, 2);
    2105:     *len = 0;
    2106:   }
    2107:   if (namelist) {
    2108:     PetscAssertPointer(namelist, 3);
    2109:     *namelist = NULL;
    2110:   }
    2111:   if (islist) {
    2112:     PetscAssertPointer(islist, 4);
    2113:     *islist = NULL;
    2114:   }
    2115:   if (dmlist) {
    2116:     PetscAssertPointer(dmlist, 5);
    2117:     *dmlist = NULL;
    2118:   }
    2119:   /*
    2120:    Is it a good idea to apply the following check across all impls?
    2121:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2122:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2123:    */
    2124:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2125:   if (!dm->ops->createfielddecomposition) {
    2126:     PetscSection section;
    2127:     PetscInt     numFields, f;

    2129:     PetscCall(DMGetLocalSection(dm, &section));
    2130:     if (section) PetscCall(PetscSectionGetNumFields(section, &numFields));
    2131:     if (section && numFields && dm->ops->createsubdm) {
    2132:       if (len) *len = numFields;
    2133:       if (namelist) PetscCall(PetscMalloc1(numFields, namelist));
    2134:       if (islist) PetscCall(PetscMalloc1(numFields, islist));
    2135:       if (dmlist) PetscCall(PetscMalloc1(numFields, dmlist));
    2136:       for (f = 0; f < numFields; ++f) {
    2137:         const char *fieldName;

    2139:         PetscCall(DMCreateSubDM(dm, 1, &f, islist ? &(*islist)[f] : NULL, dmlist ? &(*dmlist)[f] : NULL));
    2140:         if (namelist) {
    2141:           PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    2142:           PetscCall(PetscStrallocpy(fieldName, &(*namelist)[f]));
    2143:         }
    2144:       }
    2145:     } else {
    2146:       PetscCall(DMCreateFieldIS(dm, len, namelist, islist));
    2147:       /* By default there are no DMs associated with subproblems. */
    2148:       if (dmlist) *dmlist = NULL;
    2149:     }
    2150:   } else PetscUseTypeMethod(dm, createfielddecomposition, len, namelist, islist, dmlist);
    2151:   PetscFunctionReturn(PETSC_SUCCESS);
    2152: }

    2154: /*@
    2155:   DMCreateSubDM - Returns an `IS` and `DM` encapsulating a subproblem defined by the fields passed in.
    2156:   The fields are defined by `DMCreateFieldIS()`.

    2158:   Not collective

    2160:   Input Parameters:
    2161: + dm        - The `DM` object
    2162: . numFields - The number of fields to select
    2163: - fields    - The field numbers of the selected fields

    2165:   Output Parameters:
    2166: + is    - The global indices for all the degrees of freedom in the new sub `DM`, use `NULL` if not needed
    2167: - subdm - The `DM` for the subproblem, use `NULL` if not needed

    2169:   Level: intermediate

    2171:   Note:
    2172:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2174: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldIS()`, `DMCreateFieldDecomposition()`, `DMAddField()`, `DMCreateSuperDM()`, `IS`, `VecISCopy()`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    2175: @*/
    2176: PetscErrorCode DMCreateSubDM(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
    2177: {
    2178:   PetscFunctionBegin;
    2180:   PetscAssertPointer(fields, 3);
    2181:   if (is) PetscAssertPointer(is, 4);
    2182:   if (subdm) PetscAssertPointer(subdm, 5);
    2183:   PetscUseTypeMethod(dm, createsubdm, numFields, fields, is, subdm);
    2184:   PetscFunctionReturn(PETSC_SUCCESS);
    2185: }

    2187: /*@C
    2188:   DMCreateSuperDM - Returns an arrays of `IS` and a single `DM` encapsulating a superproblem defined by multiple `DM`s passed in.

    2190:   Not collective

    2192:   Input Parameters:
    2193: + dms - The `DM` objects
    2194: - n   - The number of `DM`s

    2196:   Output Parameters:
    2197: + is      - The global indices for each of subproblem within the super `DM`, or `NULL`, its length is `n`
    2198: - superdm - The `DM` for the superproblem

    2200:   Level: intermediate

    2202:   Note:
    2203:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2205: .seealso: [](ch_dmbase), `DM`, `DMCreateSubDM()`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`, `DMCreateDomainDecomposition()`
    2206: @*/
    2207: PetscErrorCode DMCreateSuperDM(DM dms[], PetscInt n, IS *is[], DM *superdm)
    2208: {
    2209:   PetscInt i;

    2211:   PetscFunctionBegin;
    2212:   PetscAssertPointer(dms, 1);
    2214:   if (is) PetscAssertPointer(is, 3);
    2215:   PetscAssertPointer(superdm, 4);
    2216:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of DMs must be nonnegative: %" PetscInt_FMT, n);
    2217:   if (n) {
    2218:     DM dm = dms[0];
    2219:     PetscCheck(dm->ops->createsuperdm, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No method createsuperdm for DM of type %s", ((PetscObject)dm)->type_name);
    2220:     PetscCall((*dm->ops->createsuperdm)(dms, n, is, superdm));
    2221:   }
    2222:   PetscFunctionReturn(PETSC_SUCCESS);
    2223: }

    2225: /*@C
    2226:   DMCreateDomainDecomposition - Returns lists of `IS` objects defining a decomposition of a
    2227:   problem into subproblems corresponding to restrictions to pairs of nested subdomains.

    2229:   Not Collective

    2231:   Input Parameter:
    2232: . dm - the `DM` object

    2234:   Output Parameters:
    2235: + n           - The number of subproblems in the domain decomposition (or `NULL` if not requested), also the length of the four arrays below
    2236: . namelist    - The name for each subdomain (or `NULL` if not requested)
    2237: . innerislist - The global indices for each inner subdomain (or `NULL`, if not requested)
    2238: . outerislist - The global indices for each outer subdomain (or `NULL`, if not requested)
    2239: - dmlist      - The `DM`s for each subdomain subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2241:   Level: intermediate

    2243:   Notes:
    2244:   Each `IS` contains the global indices of the dofs of the corresponding subdomains with in the
    2245:   dofs of the original `DM`. The inner subdomains conceptually define a nonoverlapping
    2246:   covering, while outer subdomains can overlap.

    2248:   The optional list of `DM`s define a `DM` for each subproblem.

    2250:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2251:   `PetscFree()`, every entry of `innerislist` and `outerislist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2252:   and all of the arrays should be freed with `PetscFree()`.

    2254:   Developer Notes:
    2255:   The `dmlist` is for the inner subdomains or the outer subdomains or all subdomains?

    2257:   The names are inconsistent, the hooks use `DMSubDomainHook` which is nothing like `DMCreateDomainDecomposition()` while `DMRefineHook` is used for `DMRefine()`.

    2259: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldDecomposition()`, `DMDestroy()`, `DMCreateDomainDecompositionScatters()`, `DMView()`, `DMCreateInterpolation()`,
    2260:           `DMSubDomainHookAdd()`, `DMSubDomainHookRemove()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2261: @*/
    2262: PetscErrorCode DMCreateDomainDecomposition(DM dm, PetscInt *n, char **namelist[], IS *innerislist[], IS *outerislist[], DM *dmlist[])
    2263: {
    2264:   DMSubDomainHookLink link;
    2265:   PetscInt            i, l;

    2267:   PetscFunctionBegin;
    2269:   if (n) {
    2270:     PetscAssertPointer(n, 2);
    2271:     *n = 0;
    2272:   }
    2273:   if (namelist) {
    2274:     PetscAssertPointer(namelist, 3);
    2275:     *namelist = NULL;
    2276:   }
    2277:   if (innerislist) {
    2278:     PetscAssertPointer(innerislist, 4);
    2279:     *innerislist = NULL;
    2280:   }
    2281:   if (outerislist) {
    2282:     PetscAssertPointer(outerislist, 5);
    2283:     *outerislist = NULL;
    2284:   }
    2285:   if (dmlist) {
    2286:     PetscAssertPointer(dmlist, 6);
    2287:     *dmlist = NULL;
    2288:   }
    2289:   /*
    2290:    Is it a good idea to apply the following check across all impls?
    2291:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2292:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2293:    */
    2294:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2295:   if (dm->ops->createdomaindecomposition) {
    2296:     PetscUseTypeMethod(dm, createdomaindecomposition, &l, namelist, innerislist, outerislist, dmlist);
    2297:     /* copy subdomain hooks and context over to the subdomain DMs */
    2298:     if (dmlist && *dmlist) {
    2299:       for (i = 0; i < l; i++) {
    2300:         for (link = dm->subdomainhook; link; link = link->next) {
    2301:           if (link->ddhook) PetscCall((*link->ddhook)(dm, (*dmlist)[i], link->ctx));
    2302:         }
    2303:         if (dm->ctx) (*dmlist)[i]->ctx = dm->ctx;
    2304:       }
    2305:     }
    2306:     if (n) *n = l;
    2307:   }
    2308:   PetscFunctionReturn(PETSC_SUCCESS);
    2309: }

    2311: /*@C
    2312:   DMCreateDomainDecompositionScatters - Returns scatters to the subdomain vectors from the global vector for subdomains created with
    2313:   `DMCreateDomainDecomposition()`

    2315:   Not Collective

    2317:   Input Parameters:
    2318: + dm     - the `DM` object
    2319: . n      - the number of subdomains
    2320: - subdms - the local subdomains

    2322:   Output Parameters:
    2323: + iscat - scatter from global vector to nonoverlapping global vector entries on subdomain
    2324: . oscat - scatter from global vector to overlapping global vector entries on subdomain
    2325: - gscat - scatter from global vector to local vector on subdomain (fills in ghosts)

    2327:   Level: developer

    2329:   Note:
    2330:   This is an alternative to the `iis` and `ois` arguments in `DMCreateDomainDecomposition()` that allow for the solution
    2331:   of general nonlinear problems with overlapping subdomain methods.  While merely having index sets that enable subsets
    2332:   of the residual equations to be created is fine for linear problems, nonlinear problems require local assembly of
    2333:   solution and residual data.

    2335:   Developer Note:
    2336:   Can the `subdms` input be anything or are they exactly the `DM` obtained from
    2337:   `DMCreateDomainDecomposition()`?

    2339: .seealso: [](ch_dmbase), `DM`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`
    2340: @*/
    2341: PetscErrorCode DMCreateDomainDecompositionScatters(DM dm, PetscInt n, DM subdms[], VecScatter *iscat[], VecScatter *oscat[], VecScatter *gscat[])
    2342: {
    2343:   PetscFunctionBegin;
    2345:   PetscAssertPointer(subdms, 3);
    2346:   PetscUseTypeMethod(dm, createddscatters, n, subdms, iscat, oscat, gscat);
    2347:   PetscFunctionReturn(PETSC_SUCCESS);
    2348: }

    2350: /*@
    2351:   DMRefine - Refines a `DM` object using a standard nonadaptive refinement of the underlying mesh

    2353:   Collective

    2355:   Input Parameters:
    2356: + dm   - the `DM` object
    2357: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    2359:   Output Parameter:
    2360: . dmf - the refined `DM`, or `NULL`

    2362:   Options Database Key:
    2363: . -dm_plex_cell_refiner strategy - chooses the refinement strategy, e.g. regular, tohex

    2365:   Level: developer

    2367:   Note:
    2368:   If no refinement was done, the return value is `NULL`

    2370: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    2371:           `DMRefineHookAdd()`, `DMRefineHookRemove()`
    2372: @*/
    2373: PetscErrorCode DMRefine(DM dm, MPI_Comm comm, DM *dmf)
    2374: {
    2375:   DMRefineHookLink link;

    2377:   PetscFunctionBegin;
    2379:   PetscCall(PetscLogEventBegin(DM_Refine, dm, 0, 0, 0));
    2380:   PetscUseTypeMethod(dm, refine, comm, dmf);
    2381:   if (*dmf) {
    2382:     (*dmf)->ops->creatematrix = dm->ops->creatematrix;

    2384:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmf));

    2386:     (*dmf)->ctx       = dm->ctx;
    2387:     (*dmf)->leveldown = dm->leveldown;
    2388:     (*dmf)->levelup   = dm->levelup + 1;

    2390:     PetscCall(DMSetMatType(*dmf, dm->mattype));
    2391:     for (link = dm->refinehook; link; link = link->next) {
    2392:       if (link->refinehook) PetscCall((*link->refinehook)(dm, *dmf, link->ctx));
    2393:     }
    2394:   }
    2395:   PetscCall(PetscLogEventEnd(DM_Refine, dm, 0, 0, 0));
    2396:   PetscFunctionReturn(PETSC_SUCCESS);
    2397: }

    2399: /*@C
    2400:   DMRefineHookAdd - adds a callback to be run when interpolating a nonlinear problem to a finer grid

    2402:   Logically Collective; No Fortran Support

    2404:   Input Parameters:
    2405: + coarse     - `DM` on which to run a hook when interpolating to a finer level
    2406: . refinehook - function to run when setting up the finer level
    2407: . interphook - function to run to update data on finer levels (once per `SNESSolve()`)
    2408: - ctx        - [optional] context for provide data for the hooks (may be `NULL`)

    2410:   Calling sequence of `refinehook`:
    2411: + coarse - coarse level `DM`
    2412: . fine   - fine level `DM` to interpolate problem to
    2413: - ctx    - optional function context

    2415:   Calling sequence of `interphook`:
    2416: + coarse - coarse level `DM`
    2417: . interp - matrix interpolating a coarse-level solution to the finer grid
    2418: . fine   - fine level `DM` to update
    2419: - ctx    - optional function context

    2421:   Level: advanced

    2423:   Notes:
    2424:   This function is only needed if auxiliary data that is attached to the `DM`s via, for example, `PetscObjectCompose()`, needs to be
    2425:   passed to fine grids while grid sequencing.

    2427:   The actual interpolation is done when `DMInterpolate()` is called.

    2429:   If this function is called multiple times, the hooks will be run in the order they are added.

    2431: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2432: @*/
    2433: PetscErrorCode DMRefineHookAdd(DM coarse, PetscErrorCode (*refinehook)(DM coarse, DM fine, PetscCtx ctx), PetscErrorCode (*interphook)(DM coarse, Mat interp, DM fine, PetscCtx ctx), PetscCtx ctx)
    2434: {
    2435:   DMRefineHookLink link, *p;

    2437:   PetscFunctionBegin;
    2439:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    2440:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    2441:   }
    2442:   PetscCall(PetscNew(&link));
    2443:   link->refinehook = refinehook;
    2444:   link->interphook = interphook;
    2445:   link->ctx        = ctx;
    2446:   link->next       = NULL;
    2447:   *p               = link;
    2448:   PetscFunctionReturn(PETSC_SUCCESS);
    2449: }

    2451: /*@C
    2452:   DMRefineHookRemove - remove a callback from the list of hooks, that have been set with `DMRefineHookAdd()`, to be run when interpolating
    2453:   a nonlinear problem to a finer grid

    2455:   Logically Collective; No Fortran Support

    2457:   Input Parameters:
    2458: + coarse     - the `DM` on which to run a hook when restricting to a coarser level
    2459: . refinehook - function to run when setting up a finer level
    2460: . interphook - function to run to update data on finer levels
    2461: - ctx        - [optional] application context for provide data for the hooks (may be `NULL`)

    2463:   Calling sequence of refinehook:
    2464: + coarse - the coarse `DM`
    2465: . fine   - the fine `DM`
    2466: - ctx    - context for the function

    2468:   Calling sequence of interphook:
    2469: + coarse - the coarse `DM`
    2470: . interp - the interpolation `Mat` from coarse to fine
    2471: . fine   - the fine `DM`
    2472: - ctx    - context for the function

    2474:   Level: advanced

    2476:   Note:
    2477:   This function does nothing if the hook is not in the list.

    2479: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `DMCoarsenHookRemove()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2480: @*/
    2481: PetscErrorCode DMRefineHookRemove(DM coarse, PetscErrorCode (*refinehook)(DM coarse, DM fine, PetscCtx ctx), PetscErrorCode (*interphook)(DM coarse, Mat interp, DM fine, PetscCtx ctx), PetscCtx ctx)
    2482: {
    2483:   DMRefineHookLink link, *p;

    2485:   PetscFunctionBegin;
    2487:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    2488:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) {
    2489:       link = *p;
    2490:       *p   = link->next;
    2491:       PetscCall(PetscFree(link));
    2492:       break;
    2493:     }
    2494:   }
    2495:   PetscFunctionReturn(PETSC_SUCCESS);
    2496: }

    2498: /*@
    2499:   DMInterpolate - interpolates user-defined problem data attached to a `DM` to a finer `DM` by running hooks registered by `DMRefineHookAdd()`

    2501:   Collective if any hooks are

    2503:   Input Parameters:
    2504: + coarse - coarser `DM` to use as a base
    2505: . interp - interpolation matrix, apply using `MatInterpolate()`
    2506: - fine   - finer `DM` to update

    2508:   Level: developer

    2510:   Developer Note:
    2511:   This routine is called `DMInterpolate()` while the hook is called `DMRefineHookAdd()`. It would be better to have an
    2512:   an API with consistent terminology.

    2514: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `MatInterpolate()`
    2515: @*/
    2516: PetscErrorCode DMInterpolate(DM coarse, Mat interp, DM fine)
    2517: {
    2518:   DMRefineHookLink link;

    2520:   PetscFunctionBegin;
    2521:   for (link = fine->refinehook; link; link = link->next) {
    2522:     if (link->interphook) PetscCall((*link->interphook)(coarse, interp, fine, link->ctx));
    2523:   }
    2524:   PetscFunctionReturn(PETSC_SUCCESS);
    2525: }

    2527: /*@
    2528:   DMInterpolateSolution - Interpolates a solution from a coarse mesh to a fine mesh.

    2530:   Collective

    2532:   Input Parameters:
    2533: + coarse    - coarse `DM`
    2534: . fine      - fine `DM`
    2535: . interp    - (optional) the matrix computed by `DMCreateInterpolation()`.  Implementations may not need this, but if it
    2536:             is available it can avoid some recomputation.  If it is provided, `MatInterpolate()` will be used if
    2537:             the coarse `DM` does not have a specialized implementation.
    2538: - coarseSol - solution on the coarse mesh

    2540:   Output Parameter:
    2541: . fineSol - the interpolation of coarseSol to the fine mesh

    2543:   Level: developer

    2545:   Note:
    2546:   This function exists because the interpolation of a solution vector between meshes is not always a linear
    2547:   map.  For example, if a boundary value problem has an inhomogeneous Dirichlet boundary condition that is compressed
    2548:   out of the solution vector.  Or if interpolation is inherently a nonlinear operation, such as a method using
    2549:   slope-limiting reconstruction.

    2551:   Developer Note:
    2552:   This doesn't just interpolate "solutions" so its API name is questionable.

    2554: .seealso: [](ch_dmbase), `DM`, `DMInterpolate()`, `DMCreateInterpolation()`
    2555: @*/
    2556: PetscErrorCode DMInterpolateSolution(DM coarse, DM fine, Mat interp, Vec coarseSol, Vec fineSol)
    2557: {
    2558:   PetscErrorCode (*interpsol)(DM, DM, Mat, Vec, Vec) = NULL;

    2560:   PetscFunctionBegin;

    2566:   PetscCall(PetscObjectQueryFunction((PetscObject)coarse, "DMInterpolateSolution_C", &interpsol));
    2567:   if (interpsol) {
    2568:     PetscCall((*interpsol)(coarse, fine, interp, coarseSol, fineSol));
    2569:   } else if (interp) {
    2570:     PetscCall(MatInterpolate(interp, coarseSol, fineSol));
    2571:   } else SETERRQ(PetscObjectComm((PetscObject)coarse), PETSC_ERR_SUP, "DM %s does not implement DMInterpolateSolution()", ((PetscObject)coarse)->type_name);
    2572:   PetscFunctionReturn(PETSC_SUCCESS);
    2573: }

    2575: /*@
    2576:   DMGetRefineLevel - Gets the number of refinements that have generated this `DM` from some initial `DM`.

    2578:   Not Collective

    2580:   Input Parameter:
    2581: . dm - the `DM` object

    2583:   Output Parameter:
    2584: . level - number of refinements

    2586:   Level: developer

    2588:   Note:
    2589:   This can be used, by example, to set the number of coarser levels associated with this `DM` for a multigrid solver.

    2591: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2592: @*/
    2593: PetscErrorCode DMGetRefineLevel(DM dm, PetscInt *level)
    2594: {
    2595:   PetscFunctionBegin;
    2597:   *level = dm->levelup;
    2598:   PetscFunctionReturn(PETSC_SUCCESS);
    2599: }

    2601: /*@
    2602:   DMSetRefineLevel - Sets the number of refinements that have generated this `DM`.

    2604:   Not Collective

    2606:   Input Parameters:
    2607: + dm    - the `DM` object
    2608: - level - number of refinements

    2610:   Level: advanced

    2612:   Notes:
    2613:   This value is used by `PCMG` to determine how many multigrid levels to use

    2615:   The values are usually set automatically by the process that is causing the refinements of an initial `DM` by calling this routine.

    2617: .seealso: [](ch_dmbase), `DM`, `DMGetRefineLevel()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2618: @*/
    2619: PetscErrorCode DMSetRefineLevel(DM dm, PetscInt level)
    2620: {
    2621:   PetscFunctionBegin;
    2623:   dm->levelup = level;
    2624:   PetscFunctionReturn(PETSC_SUCCESS);
    2625: }

    2627: /*@
    2628:   DMExtrude - Extrude a `DM` object from a surface

    2630:   Collective

    2632:   Input Parameters:
    2633: + dm     - the `DM` object
    2634: - layers - the number of extruded cell layers

    2636:   Output Parameter:
    2637: . dme - the extruded `DM`, or `NULL`

    2639:   Level: developer

    2641:   Note:
    2642:   If no extrusion was done, the return value is `NULL`

    2644: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`
    2645: @*/
    2646: PetscErrorCode DMExtrude(DM dm, PetscInt layers, DM *dme)
    2647: {
    2648:   PetscFunctionBegin;
    2650:   PetscUseTypeMethod(dm, extrude, layers, dme);
    2651:   if (*dme) {
    2652:     (*dme)->ops->creatematrix = dm->ops->creatematrix;
    2653:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dme));
    2654:     (*dme)->ctx = dm->ctx;
    2655:     PetscCall(DMSetMatType(*dme, dm->mattype));
    2656:   }
    2657:   PetscFunctionReturn(PETSC_SUCCESS);
    2658: }

    2660: PetscErrorCode DMGetBasisTransformDM_Internal(DM dm, DM *tdm)
    2661: {
    2662:   PetscFunctionBegin;
    2664:   PetscAssertPointer(tdm, 2);
    2665:   *tdm = dm->transformDM;
    2666:   PetscFunctionReturn(PETSC_SUCCESS);
    2667: }

    2669: PetscErrorCode DMGetBasisTransformVec_Internal(DM dm, Vec *tv)
    2670: {
    2671:   PetscFunctionBegin;
    2673:   PetscAssertPointer(tv, 2);
    2674:   *tv = dm->transform;
    2675:   PetscFunctionReturn(PETSC_SUCCESS);
    2676: }

    2678: /*@
    2679:   DMHasBasisTransform - Whether the `DM` employs a basis transformation from functions in global vectors to functions in local vectors

    2681:   Input Parameter:
    2682: . dm - The `DM`

    2684:   Output Parameter:
    2685: . flg - `PETSC_TRUE` if a basis transformation should be done

    2687:   Level: developer

    2689: .seealso: [](ch_dmbase), `DM`, `DMPlexGlobalToLocalBasis()`, `DMPlexLocalToGlobalBasis()`, `DMPlexCreateBasisRotation()`
    2690: @*/
    2691: PetscErrorCode DMHasBasisTransform(DM dm, PetscBool *flg)
    2692: {
    2693:   Vec tv;

    2695:   PetscFunctionBegin;
    2697:   PetscAssertPointer(flg, 2);
    2698:   PetscCall(DMGetBasisTransformVec_Internal(dm, &tv));
    2699:   *flg = tv ? PETSC_TRUE : PETSC_FALSE;
    2700:   PetscFunctionReturn(PETSC_SUCCESS);
    2701: }

    2703: PetscErrorCode DMConstructBasisTransform_Internal(DM dm)
    2704: {
    2705:   PetscSection s, ts;
    2706:   PetscScalar *ta;
    2707:   PetscInt     cdim, pStart, pEnd, p, Nf, f, Nc, dof;

    2709:   PetscFunctionBegin;
    2710:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    2711:   PetscCall(DMGetLocalSection(dm, &s));
    2712:   PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    2713:   PetscCall(PetscSectionGetNumFields(s, &Nf));
    2714:   PetscCall(DMClone(dm, &dm->transformDM));
    2715:   PetscCall(DMGetLocalSection(dm->transformDM, &ts));
    2716:   PetscCall(PetscSectionSetNumFields(ts, Nf));
    2717:   PetscCall(PetscSectionSetChart(ts, pStart, pEnd));
    2718:   for (f = 0; f < Nf; ++f) {
    2719:     PetscCall(PetscSectionGetFieldComponents(s, f, &Nc));
    2720:     /* We could start to label fields by their transformation properties */
    2721:     if (Nc != cdim) continue;
    2722:     for (p = pStart; p < pEnd; ++p) {
    2723:       PetscCall(PetscSectionGetFieldDof(s, p, f, &dof));
    2724:       if (!dof) continue;
    2725:       PetscCall(PetscSectionSetFieldDof(ts, p, f, PetscSqr(cdim)));
    2726:       PetscCall(PetscSectionAddDof(ts, p, PetscSqr(cdim)));
    2727:     }
    2728:   }
    2729:   PetscCall(PetscSectionSetUp(ts));
    2730:   PetscCall(DMCreateLocalVector(dm->transformDM, &dm->transform));
    2731:   PetscCall(VecGetArray(dm->transform, &ta));
    2732:   for (p = pStart; p < pEnd; ++p) {
    2733:     for (f = 0; f < Nf; ++f) {
    2734:       PetscCall(PetscSectionGetFieldDof(ts, p, f, &dof));
    2735:       if (dof) {
    2736:         PetscReal          x[3] = {0.0, 0.0, 0.0};
    2737:         PetscScalar       *tva;
    2738:         const PetscScalar *A;

    2740:         /* TODO Get quadrature point for this dual basis vector for coordinate */
    2741:         PetscCall((*dm->transformGetMatrix)(dm, x, PETSC_TRUE, &A, dm->transformCtx));
    2742:         PetscCall(DMPlexPointLocalFieldRef(dm->transformDM, p, f, ta, (void *)&tva));
    2743:         PetscCall(PetscArraycpy(tva, A, PetscSqr(cdim)));
    2744:       }
    2745:     }
    2746:   }
    2747:   PetscCall(VecRestoreArray(dm->transform, &ta));
    2748:   PetscFunctionReturn(PETSC_SUCCESS);
    2749: }

    2751: PetscErrorCode DMCopyTransform(DM dm, DM newdm)
    2752: {
    2753:   PetscFunctionBegin;
    2756:   newdm->transformCtx       = dm->transformCtx;
    2757:   newdm->transformSetUp     = dm->transformSetUp;
    2758:   newdm->transformDestroy   = NULL;
    2759:   newdm->transformGetMatrix = dm->transformGetMatrix;
    2760:   if (newdm->transformSetUp) PetscCall(DMConstructBasisTransform_Internal(newdm));
    2761:   PetscFunctionReturn(PETSC_SUCCESS);
    2762: }

    2764: /*@C
    2765:   DMGlobalToLocalHookAdd - adds a callback to be run when `DMGlobalToLocal()` is called

    2767:   Logically Collective

    2769:   Input Parameters:
    2770: + dm        - the `DM`
    2771: . beginhook - function to run at the beginning of `DMGlobalToLocalBegin()`
    2772: . endhook   - function to run after `DMGlobalToLocalEnd()` has completed
    2773: - ctx       - [optional] context for provide data for the hooks (may be `NULL`)

    2775:   Calling sequence of `beginhook`:
    2776: + dm   - global `DM`
    2777: . g    - global vector
    2778: . mode - mode
    2779: . l    - local vector
    2780: - ctx  - optional function context

    2782:   Calling sequence of `endhook`:
    2783: + dm   - global `DM`
    2784: . g    - global vector
    2785: . mode - mode
    2786: . l    - local vector
    2787: - ctx  - optional function context

    2789:   Level: advanced

    2791:   Note:
    2792:   The hook may be used to provide, for example, values that represent boundary conditions in the local vectors that do not exist on the global vector.

    2794: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocal()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2795: @*/
    2796: PetscErrorCode DMGlobalToLocalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM dm, Vec g, InsertMode mode, Vec l, PetscCtx ctx), PetscErrorCode (*endhook)(DM dm, Vec g, InsertMode mode, Vec l, PetscCtx ctx), PetscCtx ctx)
    2797: {
    2798:   DMGlobalToLocalHookLink link, *p;

    2800:   PetscFunctionBegin;
    2802:   for (p = &dm->gtolhook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    2803:   PetscCall(PetscNew(&link));
    2804:   link->beginhook = beginhook;
    2805:   link->endhook   = endhook;
    2806:   link->ctx       = ctx;
    2807:   link->next      = NULL;
    2808:   *p              = link;
    2809:   PetscFunctionReturn(PETSC_SUCCESS);
    2810: }

    2812: static PetscErrorCode DMGlobalToLocalHook_Constraints(DM dm, Vec g, InsertMode mode, Vec l, PetscCtx ctx)
    2813: {
    2814:   Mat          cMat;
    2815:   Vec          cVec, cBias;
    2816:   PetscSection section, cSec;
    2817:   PetscInt     pStart, pEnd, p, dof;

    2819:   PetscFunctionBegin;
    2820:   (void)g;
    2821:   (void)ctx;
    2823:   PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, &cBias));
    2824:   if (cMat && (mode == INSERT_VALUES || mode == INSERT_ALL_VALUES || mode == INSERT_BC_VALUES)) {
    2825:     PetscInt nRows;

    2827:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    2828:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    2829:     PetscCall(DMGetLocalSection(dm, &section));
    2830:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    2831:     PetscCall(MatMult(cMat, l, cVec));
    2832:     if (cBias) PetscCall(VecAXPY(cVec, 1., cBias));
    2833:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    2834:     for (p = pStart; p < pEnd; p++) {
    2835:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    2836:       if (dof) {
    2837:         PetscScalar *vals;
    2838:         PetscCall(VecGetValuesSection(cVec, cSec, p, &vals));
    2839:         PetscCall(VecSetValuesSection(l, section, p, vals, INSERT_ALL_VALUES));
    2840:       }
    2841:     }
    2842:     PetscCall(VecDestroy(&cVec));
    2843:   }
    2844:   PetscFunctionReturn(PETSC_SUCCESS);
    2845: }

    2847: /*@
    2848:   DMGlobalToLocal - update local vectors from global vector

    2850:   Neighbor-wise Collective

    2852:   Input Parameters:
    2853: + dm   - the `DM` object
    2854: . g    - the global vector
    2855: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2856: - l    - the local vector

    2858:   Level: beginner

    2860:   Notes:
    2861:   The communication involved in this update can be overlapped with computation by instead using
    2862:   `DMGlobalToLocalBegin()` and `DMGlobalToLocalEnd()`.

    2864:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2866: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocalHookAdd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`,
    2867:           `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`,
    2868:           `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    2869: @*/
    2870: PetscErrorCode DMGlobalToLocal(DM dm, Vec g, InsertMode mode, Vec l)
    2871: {
    2872:   PetscFunctionBegin;
    2873:   PetscCall(DMGlobalToLocalBegin(dm, g, mode, l));
    2874:   PetscCall(DMGlobalToLocalEnd(dm, g, mode, l));
    2875:   PetscFunctionReturn(PETSC_SUCCESS);
    2876: }

    2878: /*@
    2879:   DMGlobalToLocalBegin - Begins updating local vectors from global vector

    2881:   Neighbor-wise Collective

    2883:   Input Parameters:
    2884: + dm   - the `DM` object
    2885: . g    - the global vector
    2886: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2887: - l    - the local vector

    2889:   Level: intermediate

    2891:   Notes:
    2892:   The operation is completed with `DMGlobalToLocalEnd()`

    2894:   One can perform local computations between the `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()` to overlap communication and computation

    2896:   `DMGlobalToLocal()` is a short form of  `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()`

    2898:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2900: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2901: @*/
    2902: PetscErrorCode DMGlobalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    2903: {
    2904:   PetscSF                 sf;
    2905:   DMGlobalToLocalHookLink link;

    2907:   PetscFunctionBegin;
    2909:   for (link = dm->gtolhook; link; link = link->next) {
    2910:     if (link->beginhook) PetscCall((*link->beginhook)(dm, g, mode, l, link->ctx));
    2911:   }
    2912:   PetscCall(DMGetSectionSF(dm, &sf));
    2913:   if (sf) {
    2914:     const PetscScalar *gArray;
    2915:     PetscScalar       *lArray;
    2916:     PetscMemType       lmtype, gmtype;

    2918:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);
    2919:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2920:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2921:     PetscCall(PetscSFBcastWithMemTypeBegin(sf, MPIU_SCALAR, gmtype, gArray, lmtype, lArray, MPI_REPLACE));
    2922:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2923:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2924:   } else {
    2925:     PetscUseTypeMethod(dm, globaltolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2926:   }
    2927:   PetscFunctionReturn(PETSC_SUCCESS);
    2928: }

    2930: /*@
    2931:   DMGlobalToLocalEnd - Ends updating local vectors from global vector

    2933:   Neighbor-wise Collective

    2935:   Input Parameters:
    2936: + dm   - the `DM` object
    2937: . g    - the global vector
    2938: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2939: - l    - the local vector

    2941:   Level: intermediate

    2943:   Note:
    2944:   See `DMGlobalToLocalBegin()` for details.

    2946: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2947: @*/
    2948: PetscErrorCode DMGlobalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    2949: {
    2950:   PetscSF                 sf;
    2951:   const PetscScalar      *gArray;
    2952:   PetscScalar            *lArray;
    2953:   PetscBool               transform;
    2954:   DMGlobalToLocalHookLink link;
    2955:   PetscMemType            lmtype, gmtype;

    2957:   PetscFunctionBegin;
    2959:   PetscCall(DMGetSectionSF(dm, &sf));
    2960:   PetscCall(DMHasBasisTransform(dm, &transform));
    2961:   if (sf) {
    2962:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);

    2964:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2965:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2966:     PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, gArray, lArray, MPI_REPLACE));
    2967:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2968:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2969:     if (transform) PetscCall(DMPlexGlobalToLocalBasis(dm, l));
    2970:   } else {
    2971:     PetscUseTypeMethod(dm, globaltolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2972:   }
    2973:   PetscCall(DMGlobalToLocalHook_Constraints(dm, g, mode, l, NULL));
    2974:   for (link = dm->gtolhook; link; link = link->next) {
    2975:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    2976:   }
    2977:   PetscFunctionReturn(PETSC_SUCCESS);
    2978: }

    2980: /*@C
    2981:   DMLocalToGlobalHookAdd - adds a callback to be run when a local to global is called

    2983:   Logically Collective

    2985:   Input Parameters:
    2986: + dm        - the `DM`
    2987: . beginhook - function to run at the beginning of `DMLocalToGlobalBegin()`
    2988: . endhook   - function to run after `DMLocalToGlobalEnd()` has completed
    2989: - ctx       - [optional] context for provide data for the hooks (may be `NULL`)

    2991:   Calling sequence of `beginhook`:
    2992: + global - global `DM`
    2993: . l      - local vector
    2994: . mode   - mode
    2995: . g      - global vector
    2996: - ctx    - optional function context

    2998:   Calling sequence of `endhook`:
    2999: + global - global `DM`
    3000: . l      - local vector
    3001: . mode   - mode
    3002: . g      - global vector
    3003: - ctx    - optional function context

    3005:   Level: advanced

    3007: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMRefineHookAdd()`, `DMGlobalToLocalHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3008: @*/
    3009: PetscErrorCode DMLocalToGlobalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM global, Vec l, InsertMode mode, Vec g, PetscCtx ctx), PetscErrorCode (*endhook)(DM global, Vec l, InsertMode mode, Vec g, PetscCtx ctx), PetscCtx ctx)
    3010: {
    3011:   DMLocalToGlobalHookLink link, *p;

    3013:   PetscFunctionBegin;
    3015:   for (p = &dm->ltoghook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    3016:   PetscCall(PetscNew(&link));
    3017:   link->beginhook = beginhook;
    3018:   link->endhook   = endhook;
    3019:   link->ctx       = ctx;
    3020:   link->next      = NULL;
    3021:   *p              = link;
    3022:   PetscFunctionReturn(PETSC_SUCCESS);
    3023: }

    3025: static PetscErrorCode DMLocalToGlobalHook_Constraints(DM dm, Vec l, InsertMode mode, Vec g, PetscCtx ctx)
    3026: {
    3027:   PetscFunctionBegin;
    3028:   (void)g;
    3029:   (void)ctx;
    3031:   if (mode == ADD_VALUES || mode == ADD_ALL_VALUES || mode == ADD_BC_VALUES) {
    3032:     Mat          cMat;
    3033:     Vec          cVec;
    3034:     PetscInt     nRows;
    3035:     PetscSection section, cSec;
    3036:     PetscInt     pStart, pEnd, p, dof;

    3038:     PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, NULL));
    3039:     if (!cMat) PetscFunctionReturn(PETSC_SUCCESS);

    3041:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    3042:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    3043:     PetscCall(DMGetLocalSection(dm, &section));
    3044:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    3045:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    3046:     for (p = pStart; p < pEnd; p++) {
    3047:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    3048:       if (dof) {
    3049:         PetscInt     d;
    3050:         PetscScalar *vals;
    3051:         PetscCall(VecGetValuesSection(l, section, p, &vals));
    3052:         PetscCall(VecSetValuesSection(cVec, cSec, p, vals, mode));
    3053:         /* for this to be the true transpose, we have to zero the values that
    3054:          * we just extracted */
    3055:         for (d = 0; d < dof; d++) vals[d] = 0.;
    3056:       }
    3057:     }
    3058:     PetscCall(MatMultTransposeAdd(cMat, cVec, l, l));
    3059:     PetscCall(VecDestroy(&cVec));
    3060:   }
    3061:   PetscFunctionReturn(PETSC_SUCCESS);
    3062: }
    3063: /*@
    3064:   DMLocalToGlobal - updates global vectors from local vectors

    3066:   Neighbor-wise Collective

    3068:   Input Parameters:
    3069: + dm   - the `DM` object
    3070: . l    - the local vector
    3071: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3072: - g    - the global vector

    3074:   Level: beginner

    3076:   Notes:
    3077:   The communication involved in this update can be overlapped with computation by using
    3078:   `DMLocalToGlobalBegin()` and `DMLocalToGlobalEnd()`.

    3080:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3082:   `INSERT_VALUES` is not supported for `DMDA`; in that case simply compute the values directly into a global vector instead of a local one.

    3084:   Use `DMLocalToGlobalHookAdd()` to add additional operations that are performed on the data during the update process

    3086: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`, `DMLocalToGlobalHookAdd()`, `DMGlobaToLocallHookAdd()`
    3087: @*/
    3088: PetscErrorCode DMLocalToGlobal(DM dm, Vec l, InsertMode mode, Vec g)
    3089: {
    3090:   PetscFunctionBegin;
    3091:   PetscCall(DMLocalToGlobalBegin(dm, l, mode, g));
    3092:   PetscCall(DMLocalToGlobalEnd(dm, l, mode, g));
    3093:   PetscFunctionReturn(PETSC_SUCCESS);
    3094: }

    3096: /*@
    3097:   DMLocalToGlobalBegin - begins updating global vectors from local vectors

    3099:   Neighbor-wise Collective

    3101:   Input Parameters:
    3102: + dm   - the `DM` object
    3103: . l    - the local vector
    3104: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3105: - g    - the global vector

    3107:   Level: intermediate

    3109:   Notes:
    3110:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3112:   `INSERT_VALUES is` not supported for `DMDA`, in that case simply compute the values directly into a global vector instead of a local one.

    3114:   Use `DMLocalToGlobalEnd()` to complete the communication process.

    3116:   `DMLocalToGlobal()` is a short form of  `DMLocalToGlobalBegin()` and  `DMLocalToGlobalEnd()`

    3118:   `DMLocalToGlobalHookAdd()` may be used to provide additional operations that are performed during the update process.

    3120: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`
    3121: @*/
    3122: PetscErrorCode DMLocalToGlobalBegin(DM dm, Vec l, InsertMode mode, Vec g)
    3123: {
    3124:   PetscSF                 sf;
    3125:   PetscSection            s, gs;
    3126:   DMLocalToGlobalHookLink link;
    3127:   Vec                     tmpl;
    3128:   const PetscScalar      *lArray;
    3129:   PetscScalar            *gArray;
    3130:   PetscBool               isInsert, transform, l_inplace = PETSC_FALSE, g_inplace = PETSC_FALSE;
    3131:   PetscMemType            lmtype = PETSC_MEMTYPE_HOST, gmtype = PETSC_MEMTYPE_HOST;

    3133:   PetscFunctionBegin;
    3135:   for (link = dm->ltoghook; link; link = link->next) {
    3136:     if (link->beginhook) PetscCall((*link->beginhook)(dm, l, mode, g, link->ctx));
    3137:   }
    3138:   PetscCall(DMLocalToGlobalHook_Constraints(dm, l, mode, g, NULL));
    3139:   PetscCall(DMGetSectionSF(dm, &sf));
    3140:   PetscCall(DMGetLocalSection(dm, &s));
    3141:   switch (mode) {
    3142:   case INSERT_VALUES:
    3143:   case INSERT_ALL_VALUES:
    3144:   case INSERT_BC_VALUES:
    3145:     isInsert = PETSC_TRUE;
    3146:     break;
    3147:   case ADD_VALUES:
    3148:   case ADD_ALL_VALUES:
    3149:   case ADD_BC_VALUES:
    3150:     isInsert = PETSC_FALSE;
    3151:     break;
    3152:   default:
    3153:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3154:   }
    3155:   if ((sf && !isInsert) || (s && isInsert)) {
    3156:     PetscCall(DMHasBasisTransform(dm, &transform));
    3157:     if (transform) {
    3158:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3159:       PetscCall(VecCopy(l, tmpl));
    3160:       PetscCall(DMPlexLocalToGlobalBasis(dm, tmpl));
    3161:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3162:     } else if (isInsert) {
    3163:       PetscCall(VecGetArrayRead(l, &lArray));
    3164:     } else {
    3165:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, &lmtype));
    3166:       l_inplace = PETSC_TRUE;
    3167:     }
    3168:     if (s && isInsert) {
    3169:       PetscCall(VecGetArray(g, &gArray));
    3170:     } else {
    3171:       PetscCall(VecGetArrayAndMemType(g, &gArray, &gmtype));
    3172:       g_inplace = PETSC_TRUE;
    3173:     }
    3174:     if (sf && !isInsert) {
    3175:       PetscCall(PetscSFReduceWithMemTypeBegin(sf, MPIU_SCALAR, lmtype, lArray, gmtype, gArray, MPIU_SUM));
    3176:     } else if (s && isInsert) {
    3177:       PetscInt gStart, pStart, pEnd, p;

    3179:       PetscCall(DMGetGlobalSection(dm, &gs));
    3180:       PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    3181:       PetscCall(VecGetOwnershipRange(g, &gStart, NULL));
    3182:       for (p = pStart; p < pEnd; ++p) {
    3183:         PetscInt dof, gdof, cdof, gcdof, off, goff, d, e;

    3185:         PetscCall(PetscSectionGetDof(s, p, &dof));
    3186:         PetscCall(PetscSectionGetDof(gs, p, &gdof));
    3187:         PetscCall(PetscSectionGetConstraintDof(s, p, &cdof));
    3188:         PetscCall(PetscSectionGetConstraintDof(gs, p, &gcdof));
    3189:         PetscCall(PetscSectionGetOffset(s, p, &off));
    3190:         PetscCall(PetscSectionGetOffset(gs, p, &goff));
    3191:         /* Ignore off-process data and points with no global data */
    3192:         if (!gdof || goff < 0) continue;
    3193:         PetscCheck(dof == gdof, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3194:         /* If no constraints are enforced in the global vector */
    3195:         if (!gcdof) {
    3196:           for (d = 0; d < dof; ++d) gArray[goff - gStart + d] = lArray[off + d];
    3197:           /* If constraints are enforced in the global vector */
    3198:         } else if (cdof == gcdof) {
    3199:           const PetscInt *cdofs;
    3200:           PetscInt        cind = 0;

    3202:           PetscCall(PetscSectionGetConstraintIndices(s, p, &cdofs));
    3203:           for (d = 0, e = 0; d < dof; ++d) {
    3204:             if ((cind < cdof) && (d == cdofs[cind])) {
    3205:               ++cind;
    3206:               continue;
    3207:             }
    3208:             gArray[goff - gStart + e++] = lArray[off + d];
    3209:           }
    3210:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3211:       }
    3212:     }
    3213:     if (g_inplace) {
    3214:       PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3215:     } else {
    3216:       PetscCall(VecRestoreArray(g, &gArray));
    3217:     }
    3218:     if (transform) {
    3219:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3220:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3221:     } else if (l_inplace) {
    3222:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3223:     } else {
    3224:       PetscCall(VecRestoreArrayRead(l, &lArray));
    3225:     }
    3226:   } else {
    3227:     PetscUseTypeMethod(dm, localtoglobalbegin, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3228:   }
    3229:   PetscFunctionReturn(PETSC_SUCCESS);
    3230: }

    3232: /*@
    3233:   DMLocalToGlobalEnd - updates global vectors from local vectors

    3235:   Neighbor-wise Collective

    3237:   Input Parameters:
    3238: + dm   - the `DM` object
    3239: . l    - the local vector
    3240: . mode - `INSERT_VALUES` or `ADD_VALUES`
    3241: - g    - the global vector

    3243:   Level: intermediate

    3245:   Note:
    3246:   See `DMLocalToGlobalBegin()` for full details

    3248: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`
    3249: @*/
    3250: PetscErrorCode DMLocalToGlobalEnd(DM dm, Vec l, InsertMode mode, Vec g)
    3251: {
    3252:   PetscSF                 sf;
    3253:   PetscSection            s;
    3254:   DMLocalToGlobalHookLink link;
    3255:   PetscBool               isInsert, transform;

    3257:   PetscFunctionBegin;
    3259:   PetscCall(DMGetSectionSF(dm, &sf));
    3260:   PetscCall(DMGetLocalSection(dm, &s));
    3261:   switch (mode) {
    3262:   case INSERT_VALUES:
    3263:   case INSERT_ALL_VALUES:
    3264:     isInsert = PETSC_TRUE;
    3265:     break;
    3266:   case ADD_VALUES:
    3267:   case ADD_ALL_VALUES:
    3268:     isInsert = PETSC_FALSE;
    3269:     break;
    3270:   default:
    3271:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3272:   }
    3273:   if (sf && !isInsert) {
    3274:     const PetscScalar *lArray;
    3275:     PetscScalar       *gArray;
    3276:     Vec                tmpl;

    3278:     PetscCall(DMHasBasisTransform(dm, &transform));
    3279:     if (transform) {
    3280:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3281:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3282:     } else {
    3283:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, NULL));
    3284:     }
    3285:     PetscCall(VecGetArrayAndMemType(g, &gArray, NULL));
    3286:     PetscCall(PetscSFReduceEnd(sf, MPIU_SCALAR, lArray, gArray, MPIU_SUM));
    3287:     if (transform) {
    3288:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3289:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3290:     } else {
    3291:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3292:     }
    3293:     PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3294:   } else if (s && isInsert) {
    3295:   } else {
    3296:     PetscUseTypeMethod(dm, localtoglobalend, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3297:   }
    3298:   for (link = dm->ltoghook; link; link = link->next) {
    3299:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    3300:   }
    3301:   PetscFunctionReturn(PETSC_SUCCESS);
    3302: }

    3304: /*@
    3305:   DMLocalToLocalBegin - Begins the process of mapping values from a local vector (that include
    3306:   ghost points that contain irrelevant values) to another local vector where the ghost points
    3307:   in the second are set correctly from values on other MPI ranks.

    3309:   Neighbor-wise Collective

    3311:   Input Parameters:
    3312: + dm   - the `DM` object
    3313: . g    - the original local vector
    3314: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3316:   Output Parameter:
    3317: . l - the local vector with correct ghost values

    3319:   Level: intermediate

    3321:   Note:
    3322:   Must be followed by `DMLocalToLocalEnd()`.

    3324: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3325: @*/
    3326: PetscErrorCode DMLocalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    3327: {
    3328:   PetscFunctionBegin;
    3332:   PetscUseTypeMethod(dm, localtolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3333:   PetscFunctionReturn(PETSC_SUCCESS);
    3334: }

    3336: /*@
    3337:   DMLocalToLocalEnd - Maps from a local vector to another local vector where the ghost
    3338:   points in the second are set correctly. Must be preceded by `DMLocalToLocalBegin()`.

    3340:   Neighbor-wise Collective

    3342:   Input Parameters:
    3343: + dm   - the `DM` object
    3344: . g    - the original local vector
    3345: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3347:   Output Parameter:
    3348: . l - the local vector with correct ghost values

    3350:   Level: intermediate

    3352: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3353: @*/
    3354: PetscErrorCode DMLocalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    3355: {
    3356:   PetscFunctionBegin;
    3360:   PetscUseTypeMethod(dm, localtolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3361:   PetscFunctionReturn(PETSC_SUCCESS);
    3362: }

    3364: /*@
    3365:   DMCoarsen - Coarsens a `DM` object using a standard, non-adaptive coarsening of the underlying mesh

    3367:   Collective

    3369:   Input Parameters:
    3370: + dm   - the `DM` object
    3371: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    3373:   Output Parameter:
    3374: . dmc - the coarsened `DM`

    3376:   Level: developer

    3378: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    3379:           `DMCoarsenHookAdd()`, `DMCoarsenHookRemove()`
    3380: @*/
    3381: PetscErrorCode DMCoarsen(DM dm, MPI_Comm comm, DM *dmc)
    3382: {
    3383:   DMCoarsenHookLink link;

    3385:   PetscFunctionBegin;
    3387:   PetscCall(PetscLogEventBegin(DM_Coarsen, dm, 0, 0, 0));
    3388:   PetscUseTypeMethod(dm, coarsen, comm, dmc);
    3389:   if (*dmc) {
    3390:     (*dmc)->bind_below = dm->bind_below; /* Propagate this from parent DM; otherwise -dm_bind_below will be useless for multigrid cases. */
    3391:     PetscCall(DMSetCoarseDM(dm, *dmc));
    3392:     (*dmc)->ops->creatematrix = dm->ops->creatematrix;
    3393:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmc));
    3394:     (*dmc)->ctx       = dm->ctx;
    3395:     (*dmc)->levelup   = dm->levelup;
    3396:     (*dmc)->leveldown = dm->leveldown + 1;
    3397:     PetscCall(DMSetMatType(*dmc, dm->mattype));
    3398:     for (link = dm->coarsenhook; link; link = link->next) {
    3399:       if (link->coarsenhook) PetscCall((*link->coarsenhook)(dm, *dmc, link->ctx));
    3400:     }
    3401:   }
    3402:   PetscCall(PetscLogEventEnd(DM_Coarsen, dm, 0, 0, 0));
    3403:   PetscCheck(*dmc, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "NULL coarse mesh produced");
    3404:   PetscFunctionReturn(PETSC_SUCCESS);
    3405: }

    3407: /*@C
    3408:   DMCoarsenHookAdd - adds a callback to be run when restricting a nonlinear problem to the coarse grid

    3410:   Logically Collective; No Fortran Support

    3412:   Input Parameters:
    3413: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3414: . coarsenhook  - function to run when setting up a coarser level
    3415: . restricthook - function to run to update data on coarser levels (called once per `SNESSolve()`)
    3416: - ctx          - [optional] application context for provide data for the hooks (may be `NULL`)

    3418:   Calling sequence of `coarsenhook`:
    3419: + fine   - fine level `DM`
    3420: . coarse - coarse level `DM` to restrict problem to
    3421: - ctx    - optional application function context

    3423:   Calling sequence of `restricthook`:
    3424: + fine      - fine level `DM`
    3425: . mrestrict - matrix restricting a fine-level solution to the coarse grid, usually the transpose of the interpolation
    3426: . rscale    - scaling vector for restriction
    3427: . inject    - matrix restricting by injection
    3428: . coarse    - coarse level DM to update
    3429: - ctx       - optional application function context

    3431:   Level: advanced

    3433:   Notes:
    3434:   This function is only needed if auxiliary data, attached to the `DM` with `PetscObjectCompose()`, needs to be set up or passed from the fine `DM` to the coarse `DM`.

    3436:   If this function is called multiple times, the hooks will be run in the order they are added.

    3438:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3439:   extract the finest level information from its context (instead of from the `SNES`).

    3441:   The hooks are automatically called by `DMRestrict()`

    3443: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3444: @*/
    3445: PetscErrorCode DMCoarsenHookAdd(DM fine, PetscErrorCode (*coarsenhook)(DM fine, DM coarse, PetscCtx ctx), PetscErrorCode (*restricthook)(DM fine, Mat mrestrict, Vec rscale, Mat inject, DM coarse, PetscCtx ctx), PetscCtx ctx)
    3446: {
    3447:   DMCoarsenHookLink link, *p;

    3449:   PetscFunctionBegin;
    3451:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3452:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3453:   }
    3454:   PetscCall(PetscNew(&link));
    3455:   link->coarsenhook  = coarsenhook;
    3456:   link->restricthook = restricthook;
    3457:   link->ctx          = ctx;
    3458:   link->next         = NULL;
    3459:   *p                 = link;
    3460:   PetscFunctionReturn(PETSC_SUCCESS);
    3461: }

    3463: /*@C
    3464:   DMCoarsenHookRemove - remove a callback set with `DMCoarsenHookAdd()`

    3466:   Logically Collective; No Fortran Support

    3468:   Input Parameters:
    3469: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3470: . coarsenhook  - function to run when setting up a coarser level
    3471: . restricthook - function to run to update data on coarser levels
    3472: - ctx          - [optional] application context for provide data for the hooks (may be `NULL`)

    3474:   Calling sequence of `coarsenhook`:
    3475: + fine   - fine level `DM`
    3476: . coarse - coarse level `DM` to restrict problem to
    3477: - ctx    - optional application function context

    3479:   Calling sequence of `restricthook`:
    3480: + fine    - fine level `DM`
    3481: . rstrict - matrix restricting a fine-level solution to the coarse grid, usually the transpose of the interpolation
    3482: . rscale  - scaling vector for restriction
    3483: . inject  - matrix restricting by injection
    3484: . coarse  - coarse level DM to update
    3485: - ctx     - optional application function context

    3487:   Level: advanced

    3489:   Notes:
    3490:   This function does nothing if the `coarsenhook` is not in the list.

    3492:   See `DMCoarsenHookAdd()` for the calling sequence of `coarsenhook` and `restricthook`

    3494: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3495: @*/
    3496: PetscErrorCode DMCoarsenHookRemove(DM fine, PetscErrorCode (*coarsenhook)(DM fine, DM coarse, PetscCtx ctx), PetscErrorCode (*restricthook)(DM fine, Mat rstrict, Vec rscale, Mat inject, DM coarse, PetscCtx ctx), PetscCtx ctx)
    3497: {
    3498:   DMCoarsenHookLink link, *p;

    3500:   PetscFunctionBegin;
    3502:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3503:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3504:       link = *p;
    3505:       *p   = link->next;
    3506:       PetscCall(PetscFree(link));
    3507:       break;
    3508:     }
    3509:   }
    3510:   PetscFunctionReturn(PETSC_SUCCESS);
    3511: }

    3513: /*@
    3514:   DMRestrict - restricts user-defined problem data to a coarser `DM` by running hooks registered by `DMCoarsenHookAdd()`

    3516:   Collective if any hooks are

    3518:   Input Parameters:
    3519: + fine    - finer `DM` from which the data is obtained
    3520: . restrct - restriction matrix, apply using `MatRestrict()`, usually the transpose of the interpolation
    3521: . rscale  - scaling vector for restriction
    3522: . inject  - injection matrix, also use `MatRestrict()`
    3523: - coarse  - coarser `DM` to update

    3525:   Level: developer

    3527:   Developer Note:
    3528:   Though this routine is called `DMRestrict()` the hooks are added with `DMCoarsenHookAdd()`, a consistent terminology would be better

    3530: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMInterpolate()`, `DMRefineHookAdd()`
    3531: @*/
    3532: PetscErrorCode DMRestrict(DM fine, Mat restrct, Vec rscale, Mat inject, DM coarse)
    3533: {
    3534:   DMCoarsenHookLink link;

    3536:   PetscFunctionBegin;
    3537:   for (link = fine->coarsenhook; link; link = link->next) {
    3538:     if (link->restricthook) PetscCall((*link->restricthook)(fine, restrct, rscale, inject, coarse, link->ctx));
    3539:   }
    3540:   PetscFunctionReturn(PETSC_SUCCESS);
    3541: }

    3543: /*@C
    3544:   DMSubDomainHookAdd - adds a callback to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3546:   Logically Collective; No Fortran Support

    3548:   Input Parameters:
    3549: + global       - global `DM`
    3550: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3551: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3552: - ctx          - [optional] application context for provide data for the hooks (may be `NULL`)

    3554:   Calling sequence of `ddhook`:
    3555: + global - global `DM`
    3556: . block  - subdomain `DM`
    3557: - ctx    - optional application function context

    3559:   Calling sequence of `restricthook`:
    3560: + global - global `DM`
    3561: . out    - scatter to the outer (with ghost and overlap points) sub vector
    3562: . in     - scatter to sub vector values only owned locally
    3563: . block  - subdomain `DM`
    3564: - ctx    - optional application function context

    3566:   Level: advanced

    3568:   Notes:
    3569:   This function can be used if auxiliary data needs to be set up on subdomain `DM`s.

    3571:   If this function is called multiple times, the hooks will be run in the order they are added.

    3573:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3574:   extract the global information from its context (instead of from the `SNES`).

    3576:   Developer Note:
    3577:   It is unclear what "block solve" means within the definition of `restricthook`

    3579: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`, `DMCreateDomainDecomposition()`
    3580: @*/
    3581: PetscErrorCode DMSubDomainHookAdd(DM global, PetscErrorCode (*ddhook)(DM global, DM block, PetscCtx ctx), PetscErrorCode (*restricthook)(DM global, VecScatter out, VecScatter in, DM block, PetscCtx ctx), PetscCtx ctx)
    3582: {
    3583:   DMSubDomainHookLink link, *p;

    3585:   PetscFunctionBegin;
    3587:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3588:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3589:   }
    3590:   PetscCall(PetscNew(&link));
    3591:   link->restricthook = restricthook;
    3592:   link->ddhook       = ddhook;
    3593:   link->ctx          = ctx;
    3594:   link->next         = NULL;
    3595:   *p                 = link;
    3596:   PetscFunctionReturn(PETSC_SUCCESS);
    3597: }

    3599: /*@C
    3600:   DMSubDomainHookRemove - remove a callback from the list to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3602:   Logically Collective; No Fortran Support

    3604:   Input Parameters:
    3605: + global       - global `DM`
    3606: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3607: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3608: - ctx          - [optional] application context for provide data for the hooks (may be `NULL`)

    3610:   Calling sequence of `ddhook`:
    3611: + dm    - global `DM`
    3612: . block - subdomain `DM`
    3613: - ctx   - optional application function context

    3615:   Calling sequence of `restricthook`:
    3616: + dm       - global `DM`
    3617: . oscatter - scatter to the outer (with ghost and overlap points) sub vector
    3618: . gscatter - scatter to sub vector values only owned locally
    3619: . block    - subdomain `DM`
    3620: - ctx      - optional application function context

    3622:   Level: advanced

    3624: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`,
    3625:           `DMCreateDomainDecomposition()`
    3626: @*/
    3627: PetscErrorCode DMSubDomainHookRemove(DM global, PetscErrorCode (*ddhook)(DM dm, DM block, PetscCtx ctx), PetscErrorCode (*restricthook)(DM dm, VecScatter oscatter, VecScatter gscatter, DM block, PetscCtx ctx), PetscCtx ctx)
    3628: {
    3629:   DMSubDomainHookLink link, *p;

    3631:   PetscFunctionBegin;
    3633:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3634:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3635:       link = *p;
    3636:       *p   = link->next;
    3637:       PetscCall(PetscFree(link));
    3638:       break;
    3639:     }
    3640:   }
    3641:   PetscFunctionReturn(PETSC_SUCCESS);
    3642: }

    3644: /*@
    3645:   DMSubDomainRestrict - restricts user-defined problem data to a subdomain `DM` by running hooks registered by `DMSubDomainHookAdd()`

    3647:   Collective if any hooks are

    3649:   Input Parameters:
    3650: + global   - The global `DM` to use as a base
    3651: . oscatter - The scatter from domain global vector filling subdomain global vector with overlap
    3652: . gscatter - The scatter from domain global vector filling subdomain local vector with ghosts
    3653: - subdm    - The subdomain `DM` to update

    3655:   Level: developer

    3657: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMCreateDomainDecomposition()`
    3658: @*/
    3659: PetscErrorCode DMSubDomainRestrict(DM global, VecScatter oscatter, VecScatter gscatter, DM subdm)
    3660: {
    3661:   DMSubDomainHookLink link;

    3663:   PetscFunctionBegin;
    3664:   for (link = global->subdomainhook; link; link = link->next) {
    3665:     if (link->restricthook) PetscCall((*link->restricthook)(global, oscatter, gscatter, subdm, link->ctx));
    3666:   }
    3667:   PetscFunctionReturn(PETSC_SUCCESS);
    3668: }

    3670: /*@
    3671:   DMGetCoarsenLevel - Gets the number of coarsenings that have generated this `DM`.

    3673:   Not Collective

    3675:   Input Parameter:
    3676: . dm - the `DM` object

    3678:   Output Parameter:
    3679: . level - number of coarsenings

    3681:   Level: developer

    3683: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMSetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3684: @*/
    3685: PetscErrorCode DMGetCoarsenLevel(DM dm, PetscInt *level)
    3686: {
    3687:   PetscFunctionBegin;
    3689:   PetscAssertPointer(level, 2);
    3690:   *level = dm->leveldown;
    3691:   PetscFunctionReturn(PETSC_SUCCESS);
    3692: }

    3694: /*@
    3695:   DMSetCoarsenLevel - Sets the number of coarsenings that have generated this `DM`.

    3697:   Collective

    3699:   Input Parameters:
    3700: + dm    - the `DM` object
    3701: - level - number of coarsenings

    3703:   Level: developer

    3705:   Note:
    3706:   This is rarely used directly, the information is automatically set when a `DM` is created with `DMCoarsen()`

    3708: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3709: @*/
    3710: PetscErrorCode DMSetCoarsenLevel(DM dm, PetscInt level)
    3711: {
    3712:   PetscFunctionBegin;
    3714:   dm->leveldown = level;
    3715:   PetscFunctionReturn(PETSC_SUCCESS);
    3716: }

    3718: /*@
    3719:   DMRefineHierarchy - Refines a `DM` object, all levels at once

    3721:   Collective

    3723:   Input Parameters:
    3724: + dm      - the `DM` object
    3725: - nlevels - the number of levels of refinement

    3727:   Output Parameter:
    3728: . dmf - the refined `DM` hierarchy

    3730:   Level: developer

    3732: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMCoarsenHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3733: @*/
    3734: PetscErrorCode DMRefineHierarchy(DM dm, PetscInt nlevels, DM dmf[])
    3735: {
    3736:   PetscFunctionBegin;
    3738:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3739:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3740:   PetscAssertPointer(dmf, 3);
    3741:   if (dm->ops->refine && !dm->ops->refinehierarchy) {
    3742:     PetscInt i;

    3744:     PetscCall(DMRefine(dm, PetscObjectComm((PetscObject)dm), &dmf[0]));
    3745:     for (i = 1; i < nlevels; i++) PetscCall(DMRefine(dmf[i - 1], PetscObjectComm((PetscObject)dm), &dmf[i]));
    3746:   } else PetscUseTypeMethod(dm, refinehierarchy, nlevels, dmf);
    3747:   PetscFunctionReturn(PETSC_SUCCESS);
    3748: }

    3750: /*@
    3751:   DMCoarsenHierarchy - Coarsens a `DM` object, all levels at once

    3753:   Collective

    3755:   Input Parameters:
    3756: + dm      - the `DM` object
    3757: - nlevels - the number of levels of coarsening

    3759:   Output Parameter:
    3760: . dmc - the coarsened `DM` hierarchy

    3762:   Level: developer

    3764: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMRefineHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3765: @*/
    3766: PetscErrorCode DMCoarsenHierarchy(DM dm, PetscInt nlevels, DM dmc[])
    3767: {
    3768:   PetscFunctionBegin;
    3770:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3771:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3772:   PetscAssertPointer(dmc, 3);
    3773:   if (dm->ops->coarsen && !dm->ops->coarsenhierarchy) {
    3774:     PetscInt i;

    3776:     PetscCall(DMCoarsen(dm, PetscObjectComm((PetscObject)dm), &dmc[0]));
    3777:     for (i = 1; i < nlevels; i++) PetscCall(DMCoarsen(dmc[i - 1], PetscObjectComm((PetscObject)dm), &dmc[i]));
    3778:   } else PetscUseTypeMethod(dm, coarsenhierarchy, nlevels, dmc);
    3779:   PetscFunctionReturn(PETSC_SUCCESS);
    3780: }

    3782: /*@C
    3783:   DMSetApplicationContextDestroy - Sets a user function that will be called to destroy the application context when the `DM` is destroyed

    3785:   Logically Collective if the function is collective

    3787:   Input Parameters:
    3788: + dm      - the `DM` object
    3789: - destroy - the destroy function, see `PetscCtxDestroyFn` for the calling sequence

    3791:   Level: intermediate

    3793: .seealso: [](ch_dmbase), `DM`, `DMSetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`,
    3794:           `DMGetApplicationContext()`, `PetscCtxDestroyFn`
    3795: @*/
    3796: PetscErrorCode DMSetApplicationContextDestroy(DM dm, PetscCtxDestroyFn *destroy)
    3797: {
    3798:   PetscFunctionBegin;
    3800:   dm->ctxdestroy = destroy;
    3801:   PetscFunctionReturn(PETSC_SUCCESS);
    3802: }

    3804: /*@
    3805:   DMSetApplicationContext - Set a user context into a `DM` object

    3807:   Not Collective

    3809:   Input Parameters:
    3810: + dm  - the `DM` object
    3811: - ctx - the user context

    3813:   Level: intermediate

    3815:   Note:
    3816:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available
    3817:   In a multilevel solver, the user context is shared by all the `DM` in the hierarchy; it is thus not advisable
    3818:   to store objects that represent discretized quantities inside the context.

    3820:   Fortran Notes:
    3821:   This only works when the context is a Fortran derived type or a `PetscObject`. Declare `ctx` with
    3822: .vb
    3823:   type(tUsertype), pointer :: ctx
    3824: .ve

    3826: .seealso: [](ch_dmbase), `DM`, `DMGetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3827: @*/
    3828: PetscErrorCode DMSetApplicationContext(DM dm, PetscCtx ctx)
    3829: {
    3830:   PetscFunctionBegin;
    3832:   dm->ctx = ctx;
    3833:   PetscFunctionReturn(PETSC_SUCCESS);
    3834: }

    3836: /*@
    3837:   DMGetApplicationContext - Gets a user context from a `DM` object provided with `DMSetApplicationContext()`

    3839:   Not Collective

    3841:   Input Parameter:
    3842: . dm - the `DM` object

    3844:   Output Parameter:
    3845: . ctx - a pointer to the user context

    3847:   Level: intermediate

    3849:   Note:
    3850:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available

    3852:   Fortran Notes:
    3853:   This only works when the context is a Fortran derived type (it cannot be a `PetscObject`) and you **must** write a Fortran interface definition for this
    3854:   function that tells the Fortran compiler the derived data type that is returned as the `ctx` argument. For example,
    3855: .vb
    3856:   Interface DMGetApplicationContext
    3857:     Subroutine DMGetApplicationContext(dm,ctx,ierr)
    3858:   #include <petsc/finclude/petscdm.h>
    3859:       use petscdm
    3860:       DM dm
    3861:       type(tUsertype), pointer :: ctx
    3862:       PetscErrorCode ierr
    3863:     End Subroutine
    3864:   End Interface DMGetApplicationContext
    3865: .ve

    3867:   The prototype for `ctx` must be
    3868: .vb
    3869:   type(tUsertype), pointer :: ctx
    3870: .ve

    3872: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3873: @*/
    3874: PetscErrorCode DMGetApplicationContext(DM dm, PetscCtxRt ctx)
    3875: {
    3876:   PetscFunctionBegin;
    3878:   *(void **)ctx = dm->ctx;
    3879:   PetscFunctionReturn(PETSC_SUCCESS);
    3880: }

    3882: /*@C
    3883:   DMSetVariableBounds - sets a function to compute the lower and upper bound vectors for `SNESVI`.

    3885:   Logically Collective

    3887:   Input Parameters:
    3888: + dm - the `DM` object
    3889: - f  - the function that computes variable bounds used by `SNESVI` (use `NULL` to cancel a previous function that was set)

    3891:   Calling sequence of f:
    3892: + dm    - the `DM`
    3893: . lower - the vector to hold the lower bounds
    3894: - upper - the vector to hold the upper bounds

    3896:   Level: intermediate

    3898:   Developer Note:
    3899:   Should be called `DMSetComputeVIBounds()` or something similar

    3901: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`,
    3902:          `DMSetJacobian()`
    3903: @*/
    3904: PetscErrorCode DMSetVariableBounds(DM dm, PetscErrorCode (*f)(DM dm, Vec lower, Vec upper))
    3905: {
    3906:   PetscFunctionBegin;
    3908:   dm->ops->computevariablebounds = f;
    3909:   PetscFunctionReturn(PETSC_SUCCESS);
    3910: }

    3912: /*@
    3913:   DMHasVariableBounds - does the `DM` object have a variable bounds function?

    3915:   Not Collective

    3917:   Input Parameter:
    3918: . dm - the `DM` object to destroy

    3920:   Output Parameter:
    3921: . flg - `PETSC_TRUE` if the variable bounds function exists

    3923:   Level: developer

    3925: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3926: @*/
    3927: PetscErrorCode DMHasVariableBounds(DM dm, PetscBool *flg)
    3928: {
    3929:   PetscFunctionBegin;
    3931:   PetscAssertPointer(flg, 2);
    3932:   *flg = (dm->ops->computevariablebounds) ? PETSC_TRUE : PETSC_FALSE;
    3933:   PetscFunctionReturn(PETSC_SUCCESS);
    3934: }

    3936: /*@
    3937:   DMComputeVariableBounds - compute variable bounds used by `SNESVI`.

    3939:   Logically Collective

    3941:   Input Parameter:
    3942: . dm - the `DM` object

    3944:   Output Parameters:
    3945: + xl - lower bound
    3946: - xu - upper bound

    3948:   Level: advanced

    3950:   Note:
    3951:   This is generally not called by users. It calls the function provided by the user with DMSetVariableBounds()

    3953: .seealso: [](ch_dmbase), `DM`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3954: @*/
    3955: PetscErrorCode DMComputeVariableBounds(DM dm, Vec xl, Vec xu)
    3956: {
    3957:   PetscFunctionBegin;
    3961:   PetscUseTypeMethod(dm, computevariablebounds, xl, xu);
    3962:   PetscFunctionReturn(PETSC_SUCCESS);
    3963: }

    3965: /*@
    3966:   DMHasColoring - does the `DM` object have a method of providing a coloring?

    3968:   Not Collective

    3970:   Input Parameter:
    3971: . dm - the DM object

    3973:   Output Parameter:
    3974: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateColoring()`.

    3976:   Level: developer

    3978: .seealso: [](ch_dmbase), `DM`, `DMCreateColoring()`
    3979: @*/
    3980: PetscErrorCode DMHasColoring(DM dm, PetscBool *flg)
    3981: {
    3982:   PetscFunctionBegin;
    3984:   PetscAssertPointer(flg, 2);
    3985:   *flg = (dm->ops->getcoloring) ? PETSC_TRUE : PETSC_FALSE;
    3986:   PetscFunctionReturn(PETSC_SUCCESS);
    3987: }

    3989: /*@
    3990:   DMHasCreateRestriction - does the `DM` object have a method of providing a restriction?

    3992:   Not Collective

    3994:   Input Parameter:
    3995: . dm - the `DM` object

    3997:   Output Parameter:
    3998: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateRestriction()`.

    4000:   Level: developer

    4002: .seealso: [](ch_dmbase), `DM`, `DMCreateRestriction()`, `DMHasCreateInterpolation()`, `DMHasCreateInjection()`
    4003: @*/
    4004: PetscErrorCode DMHasCreateRestriction(DM dm, PetscBool *flg)
    4005: {
    4006:   PetscFunctionBegin;
    4008:   PetscAssertPointer(flg, 2);
    4009:   *flg = (dm->ops->createrestriction) ? PETSC_TRUE : PETSC_FALSE;
    4010:   PetscFunctionReturn(PETSC_SUCCESS);
    4011: }

    4013: /*@
    4014:   DMHasCreateInjection - does the `DM` object have a method of providing an injection?

    4016:   Not Collective

    4018:   Input Parameter:
    4019: . dm - the `DM` object

    4021:   Output Parameter:
    4022: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateInjection()`.

    4024:   Level: developer

    4026: .seealso: [](ch_dmbase), `DM`, `DMCreateInjection()`, `DMHasCreateRestriction()`, `DMHasCreateInterpolation()`
    4027: @*/
    4028: PetscErrorCode DMHasCreateInjection(DM dm, PetscBool *flg)
    4029: {
    4030:   PetscFunctionBegin;
    4032:   PetscAssertPointer(flg, 2);
    4033:   if (dm->ops->hascreateinjection) PetscUseTypeMethod(dm, hascreateinjection, flg);
    4034:   else *flg = (dm->ops->createinjection) ? PETSC_TRUE : PETSC_FALSE;
    4035:   PetscFunctionReturn(PETSC_SUCCESS);
    4036: }

    4038: PetscFunctionList DMList              = NULL;
    4039: PetscBool         DMRegisterAllCalled = PETSC_FALSE;

    4041: /*@
    4042:   DMSetType - Builds a `DM`, for a particular `DM` implementation.

    4044:   Collective

    4046:   Input Parameters:
    4047: + dm     - The `DM` object
    4048: - method - The name of the `DMType`, for example `DMDA`, `DMPLEX`

    4050:   Options Database Key:
    4051: . -dm_type type - Sets the `DM` type; use -help for a list of available types

    4053:   Level: intermediate

    4055:   Note:
    4056:   Of the `DM` is constructed by directly calling a function to construct a particular `DM`, for example, `DMDACreate2d()` or `DMPlexCreateBoxMesh()`

    4058: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMGetType()`, `DMCreate()`, `DMDACreate2d()`
    4059: @*/
    4060: PetscErrorCode DMSetType(DM dm, DMType method)
    4061: {
    4062:   PetscErrorCode (*r)(DM);
    4063:   PetscBool match;

    4065:   PetscFunctionBegin;
    4067:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, method, &match));
    4068:   if (match) PetscFunctionReturn(PETSC_SUCCESS);

    4070:   PetscCall(DMRegisterAll());
    4071:   PetscCall(PetscFunctionListFind(DMList, method, &r));
    4072:   PetscCheck(r, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown DM type: %s", method);

    4074:   PetscTryTypeMethod(dm, destroy);
    4075:   PetscCall(PetscMemzero(dm->ops, sizeof(*dm->ops)));
    4076:   PetscCall(PetscObjectChangeTypeName((PetscObject)dm, method));
    4077:   PetscCall((*r)(dm));
    4078:   PetscFunctionReturn(PETSC_SUCCESS);
    4079: }

    4081: /*@
    4082:   DMGetType - Gets the `DM` type name (as a string) from the `DM`.

    4084:   Not Collective

    4086:   Input Parameter:
    4087: . dm - The `DM`

    4089:   Output Parameter:
    4090: . type - The `DMType` name

    4092:   Level: intermediate

    4094:   Note:
    4095:   `type` should not be retained for later use as it will be an invalid pointer if the `DMType` of `dm` is changed.

    4097: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMSetType()`, `DMCreate()`, `PetscObjectTypeCompare()`, `PetscObjectTypeCompareAny()`
    4098: @*/
    4099: PetscErrorCode DMGetType(DM dm, DMType *type)
    4100: {
    4101:   PetscFunctionBegin;
    4103:   PetscAssertPointer(type, 2);
    4104:   PetscCall(DMRegisterAll());
    4105:   *type = ((PetscObject)dm)->type_name;
    4106:   PetscFunctionReturn(PETSC_SUCCESS);
    4107: }

    4109: /*@
    4110:   DMConvert - Converts a `DM` to another `DM`, either of the same or different type.

    4112:   Collective

    4114:   Input Parameters:
    4115: + dm      - the `DM`
    4116: - newtype - new `DM` type (use "same" for the same type)

    4118:   Output Parameter:
    4119: . M - pointer to new `DM`

    4121:   Level: intermediate

    4123:   Note:
    4124:   Cannot be used to convert a sequential `DM` to a parallel or a parallel to sequential,
    4125:   the MPI communicator of the generated `DM` is always the same as the communicator
    4126:   of the input `DM`.

    4128: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMCreate()`, `DMClone()`
    4129: @*/
    4130: PetscErrorCode DMConvert(DM dm, DMType newtype, DM *M)
    4131: {
    4132:   DM        B;
    4133:   char      convname[256];
    4134:   PetscBool sametype /*, issame */;

    4136:   PetscFunctionBegin;
    4139:   PetscAssertPointer(M, 3);
    4140:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, newtype, &sametype));
    4141:   /* PetscCall(PetscStrcmp(newtype, "same", &issame)); */
    4142:   if (sametype) {
    4143:     *M = dm;
    4144:     PetscCall(PetscObjectReference((PetscObject)dm));
    4145:     PetscFunctionReturn(PETSC_SUCCESS);
    4146:   } else {
    4147:     PetscErrorCode (*conv)(DM, DMType, DM *) = NULL;

    4149:     /*
    4150:        Order of precedence:
    4151:        1) See if a specialized converter is known to the current DM.
    4152:        2) See if a specialized converter is known to the desired DM class.
    4153:        3) See if a good general converter is registered for the desired class
    4154:        4) See if a good general converter is known for the current matrix.
    4155:        5) Use a really basic converter.
    4156:     */

    4158:     /* 1) See if a specialized converter is known to the current DM and the desired class */
    4159:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4160:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4161:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4162:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4163:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4164:     PetscCall(PetscObjectQueryFunction((PetscObject)dm, convname, &conv));
    4165:     if (conv) goto foundconv;

    4167:     /* 2)  See if a specialized converter is known to the desired DM class. */
    4168:     PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &B));
    4169:     PetscCall(DMSetType(B, newtype));
    4170:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4171:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4172:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4173:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4174:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4175:     PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
    4176:     if (conv) {
    4177:       PetscCall(DMDestroy(&B));
    4178:       goto foundconv;
    4179:     }

    4181: #if 0
    4182:     /* 3) See if a good general converter is registered for the desired class */
    4183:     conv = B->ops->convertfrom;
    4184:     PetscCall(DMDestroy(&B));
    4185:     if (conv) goto foundconv;

    4187:     /* 4) See if a good general converter is known for the current matrix */
    4188:     if (dm->ops->convert) conv = dm->ops->convert;
    4189:     if (conv) goto foundconv;
    4190: #endif

    4192:     /* 5) Use a really basic converter. */
    4193:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No conversion possible between DM types %s and %s", ((PetscObject)dm)->type_name, newtype);

    4195:   foundconv:
    4196:     PetscCall(PetscLogEventBegin(DM_Convert, dm, 0, 0, 0));
    4197:     PetscCall((*conv)(dm, newtype, M));
    4198:     /* Things that are independent of DM type: We should consult DMClone() here */
    4199:     {
    4200:       const PetscReal *maxCell, *Lstart, *L;

    4202:       PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    4203:       PetscCall(DMSetPeriodicity(*M, maxCell, Lstart, L));
    4204:       (*M)->prealloc_only = dm->prealloc_only;
    4205:       PetscCall(PetscFree((*M)->vectype));
    4206:       PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*M)->vectype));
    4207:       PetscCall(PetscFree((*M)->mattype));
    4208:       PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*M)->mattype));
    4209:     }
    4210:     PetscCall(PetscLogEventEnd(DM_Convert, dm, 0, 0, 0));
    4211:   }
    4212:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));
    4213:   PetscFunctionReturn(PETSC_SUCCESS);
    4214: }

    4216: /*@C
    4217:   DMRegister -  Adds a new `DM` type implementation

    4219:   Not Collective, No Fortran Support

    4221:   Input Parameters:
    4222: + sname    - The name of a new user-defined creation routine
    4223: - function - The creation routine itself

    4225:   Calling sequence of function:
    4226: . dm - the new `DM` that is being created

    4228:   Level: advanced

    4230:   Note:
    4231:   `DMRegister()` may be called multiple times to add several user-defined `DM`s

    4233:   Example Usage:
    4234: .vb
    4235:     DMRegister("my_da", MyDMCreate);
    4236: .ve

    4238:   Then, your `DM` type can be chosen with the procedural interface via
    4239: .vb
    4240:     DMCreate(MPI_Comm, DM *);
    4241:     DMSetType(DM,"my_da");
    4242: .ve
    4243:   or at runtime via the option
    4244: .vb
    4245:     -da_type my_da
    4246: .ve

    4248: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMSetType()`, `DMRegisterAll()`, `DMRegisterDestroy()`
    4249: @*/
    4250: PetscErrorCode DMRegister(const char sname[], PetscErrorCode (*function)(DM dm))
    4251: {
    4252:   PetscFunctionBegin;
    4253:   PetscCall(DMInitializePackage());
    4254:   PetscCall(PetscFunctionListAdd(&DMList, sname, function));
    4255:   PetscFunctionReturn(PETSC_SUCCESS);
    4256: }

    4258: /*@
    4259:   DMLoad - Loads a DM that has been stored in binary  with `DMView()`.

    4261:   Collective

    4263:   Input Parameters:
    4264: + newdm  - the newly loaded `DM`, this needs to have been created with `DMCreate()` or
    4265:            some related function before a call to `DMLoad()`.
    4266: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()` or
    4267:            `PETSCVIEWERHDF5` file viewer, obtained from `PetscViewerHDF5Open()`

    4269:   Level: intermediate

    4271:   Notes:
    4272:   The type is determined by the data in the file, any type set into the DM before this call is ignored.

    4274:   Using `PETSCVIEWERHDF5` type with `PETSC_VIEWER_HDF5_PETSC` format, one can save multiple `DMPLEX`
    4275:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    4276:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    4278: .seealso: [](ch_dmbase), `DM`, `PetscViewerBinaryOpen()`, `DMView()`, `MatLoad()`, `VecLoad()`
    4279: @*/
    4280: PetscErrorCode DMLoad(DM newdm, PetscViewer viewer)
    4281: {
    4282:   PetscBool isbinary, ishdf5;

    4284:   PetscFunctionBegin;
    4287:   PetscCall(PetscViewerCheckReadable(viewer));
    4288:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
    4289:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    4290:   PetscCall(PetscLogEventBegin(DM_Load, viewer, 0, 0, 0));
    4291:   if (isbinary) {
    4292:     PetscInt classid;
    4293:     char     type[256];

    4295:     PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
    4296:     PetscCheck(classid == DM_FILE_CLASSID, PetscObjectComm((PetscObject)newdm), PETSC_ERR_ARG_WRONG, "Not DM next in file, classid found %" PetscInt_FMT, classid);
    4297:     PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
    4298:     PetscCall(DMSetType(newdm, type));
    4299:     PetscTryTypeMethod(newdm, load, viewer);
    4300:   } else if (ishdf5) {
    4301:     PetscTryTypeMethod(newdm, load, viewer);
    4302:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen() or PetscViewerHDF5Open()");
    4303:   PetscCall(PetscLogEventEnd(DM_Load, viewer, 0, 0, 0));
    4304:   PetscFunctionReturn(PETSC_SUCCESS);
    4305: }

    4307: /* FEM Support */

    4309: PetscErrorCode DMPrintCellIndices(PetscInt c, const char name[], PetscInt len, const PetscInt x[])
    4310: {
    4311:   PetscInt f;

    4313:   PetscFunctionBegin;
    4314:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4315:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %" PetscInt_FMT " |\n", x[f]));
    4316:   PetscFunctionReturn(PETSC_SUCCESS);
    4317: }

    4319: PetscErrorCode DMPrintCellVector(PetscInt c, const char name[], PetscInt len, const PetscScalar x[])
    4320: {
    4321:   PetscInt f;

    4323:   PetscFunctionBegin;
    4324:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4325:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)PetscRealPart(x[f])));
    4326:   PetscFunctionReturn(PETSC_SUCCESS);
    4327: }

    4329: PetscErrorCode DMPrintCellVectorReal(PetscInt c, const char name[], PetscInt len, const PetscReal x[])
    4330: {
    4331:   PetscInt f;

    4333:   PetscFunctionBegin;
    4334:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4335:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)x[f]));
    4336:   PetscFunctionReturn(PETSC_SUCCESS);
    4337: }

    4339: PetscErrorCode DMPrintCellMatrix(PetscInt c, const char name[], PetscInt rows, PetscInt cols, const PetscScalar A[])
    4340: {
    4341:   PetscInt f, g;

    4343:   PetscFunctionBegin;
    4344:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4345:   for (f = 0; f < rows; ++f) {
    4346:     PetscCall(PetscPrintf(PETSC_COMM_SELF, "  |"));
    4347:     for (g = 0; g < cols; ++g) PetscCall(PetscPrintf(PETSC_COMM_SELF, " % 9.5g", (double)PetscRealPart(A[f * cols + g])));
    4348:     PetscCall(PetscPrintf(PETSC_COMM_SELF, " |\n"));
    4349:   }
    4350:   PetscFunctionReturn(PETSC_SUCCESS);
    4351: }

    4353: PetscErrorCode DMPrintLocalVec(DM dm, const char name[], PetscReal tol, Vec X)
    4354: {
    4355:   PetscInt           localSize, bs;
    4356:   PetscMPIInt        size;
    4357:   Vec                x, xglob;
    4358:   const PetscScalar *xarray;

    4360:   PetscFunctionBegin;
    4361:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    4362:   PetscCall(VecDuplicate(X, &x));
    4363:   PetscCall(VecCopy(X, x));
    4364:   PetscCall(VecFilter(x, tol));
    4365:   PetscCall(PetscPrintf(PetscObjectComm((PetscObject)dm), "%s:\n", name));
    4366:   if (size > 1) {
    4367:     PetscCall(VecGetLocalSize(x, &localSize));
    4368:     PetscCall(VecGetArrayRead(x, &xarray));
    4369:     PetscCall(VecGetBlockSize(x, &bs));
    4370:     PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)dm), bs, localSize, PETSC_DETERMINE, xarray, &xglob));
    4371:   } else {
    4372:     xglob = x;
    4373:   }
    4374:   PetscCall(VecView(xglob, PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm))));
    4375:   if (size > 1) {
    4376:     PetscCall(VecDestroy(&xglob));
    4377:     PetscCall(VecRestoreArrayRead(x, &xarray));
    4378:   }
    4379:   PetscCall(VecDestroy(&x));
    4380:   PetscFunctionReturn(PETSC_SUCCESS);
    4381: }

    4383: /*@
    4384:   DMGetLocalSection - Get the `PetscSection` encoding the local data layout for the `DM`.

    4386:   Input Parameter:
    4387: . dm - The `DM`

    4389:   Output Parameter:
    4390: . section - The `PetscSection`

    4392:   Options Database Key:
    4393: . -dm_petscsection_view - View the section created by the `DM`

    4395:   Level: intermediate

    4397:   Note:
    4398:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4400: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetGlobalSection()`
    4401: @*/
    4402: PetscErrorCode DMGetLocalSection(DM dm, PetscSection *section)
    4403: {
    4404:   PetscFunctionBegin;
    4406:   PetscAssertPointer(section, 2);
    4407:   if (!dm->localSection && dm->ops->createlocalsection) {
    4408:     PetscInt d;

    4410:     if (dm->setfromoptionscalled) {
    4411:       PetscObject       obj = (PetscObject)dm;
    4412:       PetscViewer       viewer;
    4413:       PetscViewerFormat format;
    4414:       PetscBool         flg;

    4416:       PetscCall(PetscOptionsCreateViewer(PetscObjectComm(obj), obj->options, obj->prefix, "-dm_petscds_view", &viewer, &format, &flg));
    4417:       if (flg) PetscCall(PetscViewerPushFormat(viewer, format));
    4418:       for (d = 0; d < dm->Nds; ++d) {
    4419:         PetscCall(PetscDSSetFromOptions(dm->probs[d].ds));
    4420:         if (flg) PetscCall(PetscDSView(dm->probs[d].ds, viewer));
    4421:       }
    4422:       if (flg) {
    4423:         PetscCall(PetscViewerFlush(viewer));
    4424:         PetscCall(PetscViewerPopFormat(viewer));
    4425:         PetscCall(PetscViewerDestroy(&viewer));
    4426:       }
    4427:     }
    4428:     PetscUseTypeMethod(dm, createlocalsection);
    4429:     if (dm->localSection) PetscCall(PetscObjectViewFromOptions((PetscObject)dm->localSection, NULL, "-dm_petscsection_view"));
    4430:   }
    4431:   *section = dm->localSection;
    4432:   PetscFunctionReturn(PETSC_SUCCESS);
    4433: }

    4435: /*@
    4436:   DMSetLocalSection - Set the `PetscSection` encoding the local data layout for the `DM`.

    4438:   Input Parameters:
    4439: + dm      - The `DM`
    4440: - section - The `PetscSection`

    4442:   Level: intermediate

    4444:   Note:
    4445:   Any existing Section will be destroyed

    4447: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMSetGlobalSection()`
    4448: @*/
    4449: PetscErrorCode DMSetLocalSection(DM dm, PetscSection section)
    4450: {
    4451:   PetscInt numFields = 0;
    4452:   PetscInt f;

    4454:   PetscFunctionBegin;
    4457:   PetscCall(PetscObjectReference((PetscObject)section));
    4458:   PetscCall(PetscSectionDestroy(&dm->localSection));
    4459:   dm->localSection = section;
    4460:   if (section) PetscCall(PetscSectionGetNumFields(dm->localSection, &numFields));
    4461:   if (numFields) {
    4462:     PetscCall(DMSetNumFields(dm, numFields));
    4463:     for (f = 0; f < numFields; ++f) {
    4464:       PetscObject disc;
    4465:       const char *name;

    4467:       PetscCall(PetscSectionGetFieldName(dm->localSection, f, &name));
    4468:       PetscCall(DMGetField(dm, f, NULL, &disc));
    4469:       PetscCall(PetscObjectSetName(disc, name));
    4470:     }
    4471:   }
    4472:   /* The global section and the SectionSF will be rebuilt
    4473:      in the next call to DMGetGlobalSection() and DMGetSectionSF(). */
    4474:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4475:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4476:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));

    4478:   /* Clear scratch vectors */
    4479:   PetscCall(DMClearGlobalVectors(dm));
    4480:   PetscCall(DMClearLocalVectors(dm));
    4481:   PetscCall(DMClearNamedGlobalVectors(dm));
    4482:   PetscCall(DMClearNamedLocalVectors(dm));
    4483:   PetscFunctionReturn(PETSC_SUCCESS);
    4484: }

    4486: /*@C
    4487:   DMCreateSectionPermutation - Create a permutation of the `PetscSection` chart and optionally a block structure.

    4489:   Input Parameter:
    4490: . dm - The `DM`

    4492:   Output Parameters:
    4493: + perm        - A permutation of the mesh points in the chart
    4494: - blockStarts - A high bit is set for the point that begins every block, or `NULL` for default blocking

    4496:   Level: developer

    4498: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4499: @*/
    4500: PetscErrorCode DMCreateSectionPermutation(DM dm, IS *perm, PetscBT *blockStarts)
    4501: {
    4502:   PetscFunctionBegin;
    4503:   *perm        = NULL;
    4504:   *blockStarts = NULL;
    4505:   PetscTryTypeMethod(dm, createsectionpermutation, perm, blockStarts);
    4506:   PetscFunctionReturn(PETSC_SUCCESS);
    4507: }

    4509: /*@
    4510:   DMGetDefaultConstraints - Get the `PetscSection` and `Mat` that specify the local constraint interpolation. See `DMSetDefaultConstraints()` for a description of the purpose of constraint interpolation.

    4512:   not Collective

    4514:   Input Parameter:
    4515: . dm - The `DM`

    4517:   Output Parameters:
    4518: + section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Returns `NULL` if there are no local constraints.
    4519: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section.  Returns `NULL` if there are no local constraints.
    4520: - bias    - Vector containing bias to be added to constrained dofs

    4522:   Level: advanced

    4524:   Note:
    4525:   This gets borrowed references, so the user should not destroy the `PetscSection`, `Mat`, or `Vec`.

    4527: .seealso: [](ch_dmbase), `DM`, `DMSetDefaultConstraints()`
    4528: @*/
    4529: PetscErrorCode DMGetDefaultConstraints(DM dm, PetscSection *section, Mat *mat, Vec *bias)
    4530: {
    4531:   PetscFunctionBegin;
    4533:   if (!dm->defaultConstraint.section && !dm->defaultConstraint.mat && dm->ops->createdefaultconstraints) PetscUseTypeMethod(dm, createdefaultconstraints);
    4534:   if (section) *section = dm->defaultConstraint.section;
    4535:   if (mat) *mat = dm->defaultConstraint.mat;
    4536:   if (bias) *bias = dm->defaultConstraint.bias;
    4537:   PetscFunctionReturn(PETSC_SUCCESS);
    4538: }

    4540: /*@
    4541:   DMSetDefaultConstraints - Set the `PetscSection` and `Mat` that specify the local constraint interpolation.

    4543:   Collective

    4545:   Input Parameters:
    4546: + dm      - The `DM`
    4547: . section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4548: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section:  `NULL` indicates no constraints.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4549: - bias    - A bias vector to be added to constrained values in the local vector.  `NULL` indicates no bias.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).

    4551:   Level: advanced

    4553:   Notes:
    4554:   If a constraint matrix is specified, then it is applied during `DMGlobalToLocalEnd()` when mode is `INSERT_VALUES`, `INSERT_BC_VALUES`, or `INSERT_ALL_VALUES`.  Without a constraint matrix, the local vector l returned by `DMGlobalToLocalEnd()` contains values that have been scattered from a global vector without modification; with a constraint matrix A, l is modified by computing c = A * l + bias, l[s[i]] = c[i], where the scatter s is defined by the `PetscSection` returned by `DMGetDefaultConstraints()`.

    4556:   If a constraint matrix is specified, then its adjoint is applied during `DMLocalToGlobalBegin()` when mode is `ADD_VALUES`, `ADD_BC_VALUES`, or `ADD_ALL_VALUES`.  Without a constraint matrix, the local vector l is accumulated into a global vector without modification; with a constraint matrix A, l is first modified by computing c[i] = l[s[i]], l[s[i]] = 0, l = l + A'*c, which is the adjoint of the operation described above.  Any bias, if specified, is ignored when accumulating.

    4558:   This increments the references of the `PetscSection`, `Mat`, and `Vec`, so they user can destroy them.

    4560: .seealso: [](ch_dmbase), `DM`, `DMGetDefaultConstraints()`
    4561: @*/
    4562: PetscErrorCode DMSetDefaultConstraints(DM dm, PetscSection section, Mat mat, Vec bias)
    4563: {
    4564:   PetscMPIInt result;

    4566:   PetscFunctionBegin;
    4568:   if (section) {
    4570:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)section), &result));
    4571:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint section must have local communicator");
    4572:   }
    4573:   if (mat) {
    4575:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)mat), &result));
    4576:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint matrix must have local communicator");
    4577:   }
    4578:   if (bias) {
    4580:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)bias), &result));
    4581:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint bias must have local communicator");
    4582:   }
    4583:   PetscCall(PetscObjectReference((PetscObject)section));
    4584:   PetscCall(PetscSectionDestroy(&dm->defaultConstraint.section));
    4585:   dm->defaultConstraint.section = section;
    4586:   PetscCall(PetscObjectReference((PetscObject)mat));
    4587:   PetscCall(MatDestroy(&dm->defaultConstraint.mat));
    4588:   dm->defaultConstraint.mat = mat;
    4589:   PetscCall(PetscObjectReference((PetscObject)bias));
    4590:   PetscCall(VecDestroy(&dm->defaultConstraint.bias));
    4591:   dm->defaultConstraint.bias = bias;
    4592:   PetscFunctionReturn(PETSC_SUCCESS);
    4593: }

    4595: #if defined(PETSC_USE_DEBUG)
    4596: /*
    4597:   DMDefaultSectionCheckConsistency - Check the consistentcy of the global and local sections. Generates and error if they are not consistent.

    4599:   Input Parameters:
    4600: + dm - The `DM`
    4601: . localSection - `PetscSection` describing the local data layout
    4602: - globalSection - `PetscSection` describing the global data layout

    4604:   Level: intermediate

    4606: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`
    4607: */
    4608: static PetscErrorCode DMDefaultSectionCheckConsistency_Internal(DM dm, PetscSection localSection, PetscSection globalSection)
    4609: {
    4610:   MPI_Comm        comm;
    4611:   PetscLayout     layout;
    4612:   const PetscInt *ranges;
    4613:   PetscInt        pStart, pEnd, p, nroots;
    4614:   PetscMPIInt     size, rank;
    4615:   PetscBool       valid = PETSC_TRUE, gvalid;

    4617:   PetscFunctionBegin;
    4618:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    4620:   PetscCallMPI(MPI_Comm_size(comm, &size));
    4621:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    4622:   PetscCall(PetscSectionGetChart(globalSection, &pStart, &pEnd));
    4623:   PetscCall(PetscSectionGetConstrainedStorageSize(globalSection, &nroots));
    4624:   PetscCall(PetscLayoutCreate(comm, &layout));
    4625:   PetscCall(PetscLayoutSetBlockSize(layout, 1));
    4626:   PetscCall(PetscLayoutSetLocalSize(layout, nroots));
    4627:   PetscCall(PetscLayoutSetUp(layout));
    4628:   PetscCall(PetscLayoutGetRanges(layout, &ranges));
    4629:   for (p = pStart; p < pEnd; ++p) {
    4630:     PetscInt dof, cdof, off, gdof, gcdof, goff, gsize, d;

    4632:     PetscCall(PetscSectionGetDof(localSection, p, &dof));
    4633:     PetscCall(PetscSectionGetOffset(localSection, p, &off));
    4634:     PetscCall(PetscSectionGetConstraintDof(localSection, p, &cdof));
    4635:     PetscCall(PetscSectionGetDof(globalSection, p, &gdof));
    4636:     PetscCall(PetscSectionGetConstraintDof(globalSection, p, &gcdof));
    4637:     PetscCall(PetscSectionGetOffset(globalSection, p, &goff));
    4638:     if (!gdof) continue; /* Censored point */
    4639:     if ((gdof < 0 ? -(gdof + 1) : gdof) != dof) {
    4640:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global dof %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local dof %" PetscInt_FMT "\n", rank, gdof, p, dof));
    4641:       valid = PETSC_FALSE;
    4642:     }
    4643:     if (gcdof && (gcdof != cdof)) {
    4644:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global constraints %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local constraints %" PetscInt_FMT "\n", rank, gcdof, p, cdof));
    4645:       valid = PETSC_FALSE;
    4646:     }
    4647:     if (gdof < 0) {
    4648:       gsize = gdof < 0 ? -(gdof + 1) - gcdof : gdof - gcdof;
    4649:       for (d = 0; d < gsize; ++d) {
    4650:         PetscInt offset = -(goff + 1) + d, r;

    4652:         PetscCall(PetscFindInt(offset, size + 1, ranges, &r));
    4653:         if (r < 0) r = -(r + 2);
    4654:         if ((r < 0) || (r >= size)) {
    4655:           PetscCall(PetscSynchronizedPrintf(comm, "[%d]Point %" PetscInt_FMT " mapped to invalid process %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ")\n", rank, p, r, gdof, goff));
    4656:           valid = PETSC_FALSE;
    4657:           break;
    4658:         }
    4659:       }
    4660:     }
    4661:   }
    4662:   PetscCall(PetscLayoutDestroy(&layout));
    4663:   PetscCall(PetscSynchronizedFlush(comm, NULL));
    4664:   PetscCallMPI(MPIU_Allreduce(&valid, &gvalid, 1, MPI_C_BOOL, MPI_LAND, comm));
    4665:   if (!gvalid) {
    4666:     PetscCall(DMView(dm, NULL));
    4667:     SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Inconsistent local and global sections");
    4668:   }
    4669:   PetscFunctionReturn(PETSC_SUCCESS);
    4670: }
    4671: #endif

    4673: PetscErrorCode DMGetIsoperiodicPointSF_Internal(DM dm, PetscSF *sf)
    4674: {
    4675:   PetscErrorCode (*f)(DM, PetscSF *);

    4677:   PetscFunctionBegin;
    4679:   PetscAssertPointer(sf, 2);
    4680:   PetscCall(PetscObjectQueryFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", &f));
    4681:   if (f) PetscCall(f(dm, sf));
    4682:   else *sf = dm->sf;
    4683:   PetscFunctionReturn(PETSC_SUCCESS);
    4684: }

    4686: /*@
    4687:   DMGetGlobalSection - Get the `PetscSection` encoding the global data layout for the `DM`.

    4689:   Collective

    4691:   Input Parameter:
    4692: . dm - The `DM`

    4694:   Output Parameter:
    4695: . section - The `PetscSection`

    4697:   Level: intermediate

    4699:   Note:
    4700:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4702: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetLocalSection()`
    4703: @*/
    4704: PetscErrorCode DMGetGlobalSection(DM dm, PetscSection *section)
    4705: {
    4706:   PetscFunctionBegin;
    4708:   PetscAssertPointer(section, 2);
    4709:   if (!dm->globalSection) {
    4710:     PetscSection s;
    4711:     PetscSF      sf;

    4713:     PetscCall(DMGetLocalSection(dm, &s));
    4714:     PetscCheck(s, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a default PetscSection in order to create a global PetscSection");
    4715:     PetscCheck(dm->sf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a point PetscSF in order to create a global PetscSection");
    4716:     PetscCall(DMGetIsoperiodicPointSF_Internal(dm, &sf));
    4717:     PetscCall(PetscSectionCreateGlobalSection(s, sf, PETSC_TRUE, PETSC_FALSE, PETSC_FALSE, &dm->globalSection));
    4718:     PetscCall(PetscLayoutDestroy(&dm->map));
    4719:     PetscCall(PetscSectionGetValueLayout(PetscObjectComm((PetscObject)dm), dm->globalSection, &dm->map));
    4720:     PetscCall(PetscSectionViewFromOptions(dm->globalSection, NULL, "-global_section_view"));
    4721:   }
    4722:   *section = dm->globalSection;
    4723:   PetscFunctionReturn(PETSC_SUCCESS);
    4724: }

    4726: /*@
    4727:   DMSetGlobalSection - Set the `PetscSection` encoding the global data layout for the `DM`.

    4729:   Input Parameters:
    4730: + dm      - The `DM`
    4731: - section - The PetscSection, or `NULL`

    4733:   Level: intermediate

    4735:   Note:
    4736:   Any existing `PetscSection` will be destroyed

    4738: .seealso: [](ch_dmbase), `DM`, `DMGetGlobalSection()`, `DMSetLocalSection()`
    4739: @*/
    4740: PetscErrorCode DMSetGlobalSection(DM dm, PetscSection section)
    4741: {
    4742:   PetscFunctionBegin;
    4745:   PetscCall(PetscObjectReference((PetscObject)section));
    4746:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4747:   dm->globalSection = section;
    4748: #if defined(PETSC_USE_DEBUG)
    4749:   if (section) PetscCall(DMDefaultSectionCheckConsistency_Internal(dm, dm->localSection, section));
    4750: #endif
    4751:   /* Clear global scratch vectors and sectionSF */
    4752:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4753:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4754:   PetscCall(DMClearGlobalVectors(dm));
    4755:   PetscCall(DMClearNamedGlobalVectors(dm));
    4756:   PetscFunctionReturn(PETSC_SUCCESS);
    4757: }

    4759: /*@
    4760:   DMGetSectionSF - Get the `PetscSF` encoding the parallel dof overlap for the `DM`. If it has not been set,
    4761:   it is created from the default `PetscSection` layouts in the `DM`.

    4763:   Input Parameter:
    4764: . dm - The `DM`

    4766:   Output Parameter:
    4767: . sf - The `PetscSF`

    4769:   Level: intermediate

    4771:   Note:
    4772:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4774: .seealso: [](ch_dmbase), `DM`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4775: @*/
    4776: PetscErrorCode DMGetSectionSF(DM dm, PetscSF *sf)
    4777: {
    4778:   PetscInt nroots;

    4780:   PetscFunctionBegin;
    4782:   PetscAssertPointer(sf, 2);
    4783:   if (!dm->sectionSF) PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4784:   PetscCall(PetscSFGetGraph(dm->sectionSF, &nroots, NULL, NULL, NULL));
    4785:   if (nroots < 0) {
    4786:     PetscSection section, gSection;

    4788:     PetscCall(DMGetLocalSection(dm, &section));
    4789:     if (section) {
    4790:       PetscCall(DMGetGlobalSection(dm, &gSection));
    4791:       PetscCall(DMCreateSectionSF(dm, section, gSection));
    4792:     } else {
    4793:       *sf = NULL;
    4794:       PetscFunctionReturn(PETSC_SUCCESS);
    4795:     }
    4796:   }
    4797:   *sf = dm->sectionSF;
    4798:   PetscFunctionReturn(PETSC_SUCCESS);
    4799: }

    4801: /*@
    4802:   DMSetSectionSF - Set the `PetscSF` encoding the parallel dof overlap for the `DM`

    4804:   Input Parameters:
    4805: + dm - The `DM`
    4806: - sf - The `PetscSF`

    4808:   Level: intermediate

    4810:   Note:
    4811:   Any previous `PetscSF` is destroyed

    4813: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMCreateSectionSF()`
    4814: @*/
    4815: PetscErrorCode DMSetSectionSF(DM dm, PetscSF sf)
    4816: {
    4817:   PetscFunctionBegin;
    4820:   PetscCall(PetscObjectReference((PetscObject)sf));
    4821:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4822:   dm->sectionSF = sf;
    4823:   PetscFunctionReturn(PETSC_SUCCESS);
    4824: }

    4826: /*@
    4827:   DMCreateSectionSF - Create the `PetscSF` encoding the parallel dof overlap for the `DM` based upon the `PetscSection`s
    4828:   describing the data layout.

    4830:   Input Parameters:
    4831: + dm            - The `DM`
    4832: . localSection  - `PetscSection` describing the local data layout
    4833: - globalSection - `PetscSection` describing the global data layout

    4835:   Level: developer

    4837:   Note:
    4838:   One usually uses `DMGetSectionSF()` to obtain the `PetscSF`

    4840:   Developer Note:
    4841:   Since this routine has for arguments the two sections from the `DM` and puts the resulting `PetscSF`
    4842:   directly into the `DM`, perhaps this function should not take the local and global sections as
    4843:   input and should just obtain them from the `DM`? Plus PETSc creation functions return the thing
    4844:   they create, this returns nothing

    4846: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4847: @*/
    4848: PetscErrorCode DMCreateSectionSF(DM dm, PetscSection localSection, PetscSection globalSection)
    4849: {
    4850:   PetscFunctionBegin;
    4852:   PetscCall(PetscSFSetGraphSection(dm->sectionSF, localSection, globalSection));
    4853:   PetscFunctionReturn(PETSC_SUCCESS);
    4854: }

    4856: /*@
    4857:   DMGetPointSF - Get the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4859:   Not collective but the resulting `PetscSF` is collective

    4861:   Input Parameter:
    4862: . dm - The `DM`

    4864:   Output Parameter:
    4865: . sf - The `PetscSF`

    4867:   Level: intermediate

    4869:   Note:
    4870:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4872: .seealso: [](ch_dmbase), `DM`, `DMSetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4873: @*/
    4874: PetscErrorCode DMGetPointSF(DM dm, PetscSF *sf)
    4875: {
    4876:   PetscFunctionBegin;
    4878:   PetscAssertPointer(sf, 2);
    4879:   *sf = dm->sf;
    4880:   PetscFunctionReturn(PETSC_SUCCESS);
    4881: }

    4883: /*@
    4884:   DMSetPointSF - Set the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4886:   Collective

    4888:   Input Parameters:
    4889: + dm - The `DM`
    4890: - sf - The `PetscSF`

    4892:   Level: intermediate

    4894: .seealso: [](ch_dmbase), `DM`, `DMGetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4895: @*/
    4896: PetscErrorCode DMSetPointSF(DM dm, PetscSF sf)
    4897: {
    4898:   PetscFunctionBegin;
    4901:   PetscCall(PetscObjectReference((PetscObject)sf));
    4902:   PetscCall(PetscSFDestroy(&dm->sf));
    4903:   dm->sf = sf;
    4904:   PetscFunctionReturn(PETSC_SUCCESS);
    4905: }

    4907: /*@
    4908:   DMGetNaturalSF - Get the `PetscSF` encoding the map back to the original mesh ordering

    4910:   Input Parameter:
    4911: . dm - The `DM`

    4913:   Output Parameter:
    4914: . sf - The `PetscSF`

    4916:   Level: intermediate

    4918:   Note:
    4919:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4921: .seealso: [](ch_dmbase), `DM`, `DMSetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4922: @*/
    4923: PetscErrorCode DMGetNaturalSF(DM dm, PetscSF *sf)
    4924: {
    4925:   PetscFunctionBegin;
    4927:   PetscAssertPointer(sf, 2);
    4928:   *sf = dm->sfNatural;
    4929:   PetscFunctionReturn(PETSC_SUCCESS);
    4930: }

    4932: /*@
    4933:   DMSetNaturalSF - Set the PetscSF encoding the map back to the original mesh ordering

    4935:   Input Parameters:
    4936: + dm - The DM
    4937: - sf - The PetscSF

    4939:   Level: intermediate

    4941: .seealso: [](ch_dmbase), `DM`, `DMGetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4942: @*/
    4943: PetscErrorCode DMSetNaturalSF(DM dm, PetscSF sf)
    4944: {
    4945:   PetscFunctionBegin;
    4948:   PetscCall(PetscObjectReference((PetscObject)sf));
    4949:   PetscCall(PetscSFDestroy(&dm->sfNatural));
    4950:   dm->sfNatural = sf;
    4951:   PetscFunctionReturn(PETSC_SUCCESS);
    4952: }

    4954: static PetscErrorCode DMSetDefaultAdjacency_Private(DM dm, PetscInt f, PetscObject disc)
    4955: {
    4956:   PetscClassId id;

    4958:   PetscFunctionBegin;
    4959:   PetscCall(PetscObjectGetClassId(disc, &id));
    4960:   if (id == PETSCFE_CLASSID) PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4961:   else if (id == PETSCFV_CLASSID) PetscCall(DMSetAdjacency(dm, f, PETSC_TRUE, PETSC_FALSE));
    4962:   else PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4963:   PetscFunctionReturn(PETSC_SUCCESS);
    4964: }

    4966: static PetscErrorCode DMFieldEnlarge_Static(DM dm, PetscInt NfNew)
    4967: {
    4968:   RegionField *tmpr;
    4969:   PetscInt     Nf = dm->Nf, f;

    4971:   PetscFunctionBegin;
    4972:   if (Nf >= NfNew) PetscFunctionReturn(PETSC_SUCCESS);
    4973:   PetscCall(PetscMalloc1(NfNew, &tmpr));
    4974:   for (f = 0; f < Nf; ++f) tmpr[f] = dm->fields[f];
    4975:   for (f = Nf; f < NfNew; ++f) {
    4976:     tmpr[f].disc        = NULL;
    4977:     tmpr[f].label       = NULL;
    4978:     tmpr[f].avoidTensor = PETSC_FALSE;
    4979:   }
    4980:   PetscCall(PetscFree(dm->fields));
    4981:   dm->Nf     = NfNew;
    4982:   dm->fields = tmpr;
    4983:   PetscFunctionReturn(PETSC_SUCCESS);
    4984: }

    4986: /*@
    4987:   DMClearFields - Remove all fields from the `DM`

    4989:   Logically Collective

    4991:   Input Parameter:
    4992: . dm - The `DM`

    4994:   Level: intermediate

    4996: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetNumFields()`, `DMSetField()`
    4997: @*/
    4998: PetscErrorCode DMClearFields(DM dm)
    4999: {
    5000:   PetscInt f;

    5002:   PetscFunctionBegin;
    5004:   if (!dm->fields) PetscFunctionReturn(PETSC_SUCCESS); // DMDA does not use fields field in DM
    5005:   for (f = 0; f < dm->Nf; ++f) {
    5006:     PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    5007:     PetscCall(DMLabelDestroy(&dm->fields[f].label));
    5008:   }
    5009:   PetscCall(PetscFree(dm->fields));
    5010:   dm->fields = NULL;
    5011:   dm->Nf     = 0;
    5012:   PetscFunctionReturn(PETSC_SUCCESS);
    5013: }

    5015: /*@
    5016:   DMGetNumFields - Get the number of fields in the `DM`

    5018:   Not Collective

    5020:   Input Parameter:
    5021: . dm - The `DM`

    5023:   Output Parameter:
    5024: . numFields - The number of fields

    5026:   Level: intermediate

    5028: .seealso: [](ch_dmbase), `DM`, `DMSetNumFields()`, `DMSetField()`
    5029: @*/
    5030: PetscErrorCode DMGetNumFields(DM dm, PetscInt *numFields)
    5031: {
    5032:   PetscFunctionBegin;
    5034:   PetscAssertPointer(numFields, 2);
    5035:   *numFields = dm->Nf;
    5036:   PetscFunctionReturn(PETSC_SUCCESS);
    5037: }

    5039: /*@
    5040:   DMSetNumFields - Set the number of fields in the `DM`

    5042:   Logically Collective

    5044:   Input Parameters:
    5045: + dm        - The `DM`
    5046: - numFields - The number of fields

    5048:   Level: intermediate

    5050: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetField()`
    5051: @*/
    5052: PetscErrorCode DMSetNumFields(DM dm, PetscInt numFields)
    5053: {
    5054:   PetscInt Nf, f;

    5056:   PetscFunctionBegin;
    5058:   PetscCall(DMGetNumFields(dm, &Nf));
    5059:   for (f = Nf; f < numFields; ++f) {
    5060:     PetscContainer obj;

    5062:     PetscCall(PetscContainerCreate(PetscObjectComm((PetscObject)dm), &obj));
    5063:     PetscCall(DMAddField(dm, NULL, (PetscObject)obj));
    5064:     PetscCall(PetscContainerDestroy(&obj));
    5065:   }
    5066:   PetscFunctionReturn(PETSC_SUCCESS);
    5067: }

    5069: /*@
    5070:   DMGetField - Return the `DMLabel` and discretization object for a given `DM` field

    5072:   Not Collective

    5074:   Input Parameters:
    5075: + dm - The `DM`
    5076: - f  - The field number

    5078:   Output Parameters:
    5079: + label - The label indicating the support of the field, or `NULL` for the entire mesh (pass in `NULL` if not needed)
    5080: - disc  - The discretization object (pass in `NULL` if not needed)

    5082:   Level: intermediate

    5084: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`
    5085: @*/
    5086: PetscErrorCode DMGetField(DM dm, PetscInt f, DMLabel *label, PetscObject *disc)
    5087: {
    5088:   PetscFunctionBegin;
    5090:   PetscAssertPointer(disc, 4);
    5091:   PetscCheck((f >= 0) && (f < dm->Nf), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5092:   if (!dm->fields) {
    5093:     if (label) *label = NULL;
    5094:     if (disc) *disc = NULL;
    5095:   } else { // some DM such as DMDA do not have dm->fields
    5096:     if (label) *label = dm->fields[f].label;
    5097:     if (disc) *disc = dm->fields[f].disc;
    5098:   }
    5099:   PetscFunctionReturn(PETSC_SUCCESS);
    5100: }

    5102: /* Does not clear the DS */
    5103: PetscErrorCode DMSetField_Internal(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5104: {
    5105:   PetscFunctionBegin;
    5106:   PetscCall(DMFieldEnlarge_Static(dm, f + 1));
    5107:   PetscCall(DMLabelDestroy(&dm->fields[f].label));
    5108:   PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    5109:   dm->fields[f].label = label;
    5110:   dm->fields[f].disc  = disc;
    5111:   PetscCall(PetscObjectReference((PetscObject)label));
    5112:   PetscCall(PetscObjectReference(disc));
    5113:   PetscFunctionReturn(PETSC_SUCCESS);
    5114: }

    5116: /*@
    5117:   DMSetField - Set the discretization object for a given `DM` field. Usually one would call `DMAddField()` which automatically handles
    5118:   the field numbering.

    5120:   Logically Collective

    5122:   Input Parameters:
    5123: + dm    - The `DM`
    5124: . f     - The field number
    5125: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5126: - disc  - The discretization object

    5128:   Level: intermediate

    5130: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`
    5131: @*/
    5132: PetscErrorCode DMSetField(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5133: {
    5134:   PetscFunctionBegin;
    5138:   PetscCheck(f >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be non-negative", f);
    5139:   PetscCall(DMSetField_Internal(dm, f, label, disc));
    5140:   PetscCall(DMSetDefaultAdjacency_Private(dm, f, disc));
    5141:   PetscCall(DMClearDS(dm));
    5142:   PetscFunctionReturn(PETSC_SUCCESS);
    5143: }

    5145: /*@
    5146:   DMAddField - Add a field to a `DM` object. A field is a function space defined by of a set of discretization points (geometric entities)
    5147:   and a discretization object that defines the function space associated with those points.

    5149:   Logically Collective

    5151:   Input Parameters:
    5152: + dm    - The `DM`
    5153: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5154: - disc  - The discretization object

    5156:   Level: intermediate

    5158:   Notes:
    5159:   The label already exists or will be added to the `DM` with `DMSetLabel()`.

    5161:   For example, a piecewise continuous pressure field can be defined by coefficients at the cell centers of a mesh and piecewise constant functions
    5162:   within each cell. Thus a specific function in the space is defined by the combination of a `Vec` containing the coefficients, a `DM` defining the
    5163:   geometry entities, a `DMLabel` indicating a subset of those geometric entities, and a discretization object, such as a `PetscFE`.

    5165:   Fortran Note:
    5166:   Use the argument `PetscObjectCast(disc)` as the second argument

    5168: .seealso: [](ch_dmbase), `DM`, `DMSetLabel()`, `DMSetField()`, `DMGetField()`, `PetscFE`
    5169: @*/
    5170: PetscErrorCode DMAddField(DM dm, DMLabel label, PetscObject disc)
    5171: {
    5172:   PetscInt Nf = dm->Nf;

    5174:   PetscFunctionBegin;
    5178:   PetscCall(DMFieldEnlarge_Static(dm, Nf + 1));
    5179:   dm->fields[Nf].label = label;
    5180:   dm->fields[Nf].disc  = disc;
    5181:   PetscCall(PetscObjectReference((PetscObject)label));
    5182:   PetscCall(PetscObjectReference(disc));
    5183:   PetscCall(DMSetDefaultAdjacency_Private(dm, Nf, disc));
    5184:   PetscCall(DMClearDS(dm));
    5185:   PetscFunctionReturn(PETSC_SUCCESS);
    5186: }

    5188: /*@
    5189:   DMSetFieldAvoidTensor - Set flag to avoid defining the field on tensor cells

    5191:   Logically Collective

    5193:   Input Parameters:
    5194: + dm          - The `DM`
    5195: . f           - The field index
    5196: - avoidTensor - `PETSC_TRUE` to skip defining the field on tensor cells

    5198:   Level: intermediate

    5200: .seealso: [](ch_dmbase), `DM`, `DMGetFieldAvoidTensor()`, `DMSetField()`, `DMGetField()`
    5201: @*/
    5202: PetscErrorCode DMSetFieldAvoidTensor(DM dm, PetscInt f, PetscBool avoidTensor)
    5203: {
    5204:   PetscFunctionBegin;
    5205:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5206:   dm->fields[f].avoidTensor = avoidTensor;
    5207:   PetscFunctionReturn(PETSC_SUCCESS);
    5208: }

    5210: /*@
    5211:   DMGetFieldAvoidTensor - Get flag to avoid defining the field on tensor cells

    5213:   Not Collective

    5215:   Input Parameters:
    5216: + dm - The `DM`
    5217: - f  - The field index

    5219:   Output Parameter:
    5220: . avoidTensor - The flag to avoid defining the field on tensor cells

    5222:   Level: intermediate

    5224: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`, `DMGetField()`, `DMSetFieldAvoidTensor()`
    5225: @*/
    5226: PetscErrorCode DMGetFieldAvoidTensor(DM dm, PetscInt f, PetscBool *avoidTensor)
    5227: {
    5228:   PetscFunctionBegin;
    5229:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5230:   *avoidTensor = dm->fields[f].avoidTensor;
    5231:   PetscFunctionReturn(PETSC_SUCCESS);
    5232: }

    5234: /*@
    5235:   DMCopyFields - Copy the discretizations for the `DM` into another `DM`

    5237:   Collective

    5239:   Input Parameters:
    5240: + dm        - The `DM`
    5241: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    5242: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    5244:   Output Parameter:
    5245: . newdm - The `DM`

    5247:   Level: advanced

    5249: .seealso: [](ch_dmbase), `DM`, `DMGetField()`, `DMSetField()`, `DMAddField()`, `DMCopyDS()`, `DMGetDS()`, `DMGetCellDS()`
    5250: @*/
    5251: PetscErrorCode DMCopyFields(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    5252: {
    5253:   PetscInt Nf, f;

    5255:   PetscFunctionBegin;
    5256:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    5257:   PetscCall(DMGetNumFields(dm, &Nf));
    5258:   PetscCall(DMClearFields(newdm));
    5259:   for (f = 0; f < Nf; ++f) {
    5260:     DMLabel      label;
    5261:     PetscObject  field;
    5262:     PetscClassId id;
    5263:     PetscBool    useCone, useClosure;

    5265:     PetscCall(DMGetField(dm, f, &label, &field));
    5266:     PetscCall(PetscObjectGetClassId(field, &id));
    5267:     if (id == PETSCFE_CLASSID) {
    5268:       PetscFE newfe;

    5270:       PetscCall(PetscFELimitDegree((PetscFE)field, minDegree, maxDegree, &newfe));
    5271:       PetscCall(DMSetField(newdm, f, label, (PetscObject)newfe));
    5272:       PetscCall(PetscFEDestroy(&newfe));
    5273:     } else {
    5274:       PetscCall(DMSetField(newdm, f, label, field));
    5275:     }
    5276:     PetscCall(DMGetAdjacency(dm, f, &useCone, &useClosure));
    5277:     PetscCall(DMSetAdjacency(newdm, f, useCone, useClosure));
    5278:   }
    5279:   // Create nullspace constructor slots
    5280:   if (dm->nullspaceConstructors) {
    5281:     PetscCall(PetscFree2(newdm->nullspaceConstructors, newdm->nearnullspaceConstructors));
    5282:     PetscCall(PetscCalloc2(Nf, &newdm->nullspaceConstructors, Nf, &newdm->nearnullspaceConstructors));
    5283:   }
    5284:   PetscFunctionReturn(PETSC_SUCCESS);
    5285: }

    5287: /*@
    5288:   DMGetAdjacency - Returns the flags for determining variable influence

    5290:   Not Collective

    5292:   Input Parameters:
    5293: + dm - The `DM` object
    5294: - f  - The field number, or `PETSC_DEFAULT` for the default adjacency

    5296:   Output Parameters:
    5297: + useCone    - Flag for variable influence starting with the cone operation
    5298: - useClosure - Flag for variable influence using transitive closure

    5300:   Level: developer

    5302:   Notes:
    5303: .vb
    5304:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5305:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5306:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5307: .ve
    5308:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5310: .seealso: [](ch_dmbase), `DM`, `DMSetAdjacency()`, `DMGetField()`, `DMSetField()`
    5311: @*/
    5312: PetscErrorCode DMGetAdjacency(DM dm, PetscInt f, PetscBool *useCone, PetscBool *useClosure)
    5313: {
    5314:   PetscFunctionBegin;
    5316:   if (useCone) PetscAssertPointer(useCone, 3);
    5317:   if (useClosure) PetscAssertPointer(useClosure, 4);
    5318:   if (f < 0) {
    5319:     if (useCone) *useCone = dm->adjacency[0];
    5320:     if (useClosure) *useClosure = dm->adjacency[1];
    5321:   } else {
    5322:     PetscInt Nf;

    5324:     PetscCall(DMGetNumFields(dm, &Nf));
    5325:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5326:     if (useCone) *useCone = dm->fields[f].adjacency[0];
    5327:     if (useClosure) *useClosure = dm->fields[f].adjacency[1];
    5328:   }
    5329:   PetscFunctionReturn(PETSC_SUCCESS);
    5330: }

    5332: /*@
    5333:   DMSetAdjacency - Set the flags for determining variable influence

    5335:   Not Collective

    5337:   Input Parameters:
    5338: + dm         - The `DM` object
    5339: . f          - The field number
    5340: . useCone    - Flag for variable influence starting with the cone operation
    5341: - useClosure - Flag for variable influence using transitive closure

    5343:   Level: developer

    5345:   Notes:
    5346: .vb
    5347:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5348:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5349:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5350: .ve
    5351:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5353: .seealso: [](ch_dmbase), `DM`, `DMGetAdjacency()`, `DMGetField()`, `DMSetField()`
    5354: @*/
    5355: PetscErrorCode DMSetAdjacency(DM dm, PetscInt f, PetscBool useCone, PetscBool useClosure)
    5356: {
    5357:   PetscFunctionBegin;
    5359:   if (f < 0) {
    5360:     dm->adjacency[0] = useCone;
    5361:     dm->adjacency[1] = useClosure;
    5362:   } else {
    5363:     PetscInt Nf;

    5365:     PetscCall(DMGetNumFields(dm, &Nf));
    5366:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5367:     dm->fields[f].adjacency[0] = useCone;
    5368:     dm->fields[f].adjacency[1] = useClosure;
    5369:   }
    5370:   PetscFunctionReturn(PETSC_SUCCESS);
    5371: }

    5373: /*@
    5374:   DMGetBasicAdjacency - Returns the flags for determining variable influence, using either the default or field 0 if it is defined

    5376:   Not collective

    5378:   Input Parameter:
    5379: . dm - The `DM` object

    5381:   Output Parameters:
    5382: + useCone    - Flag for variable influence starting with the cone operation
    5383: - useClosure - Flag for variable influence using transitive closure

    5385:   Level: developer

    5387:   Notes:
    5388: .vb
    5389:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5390:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5391:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5392: .ve

    5394: .seealso: [](ch_dmbase), `DM`, `DMSetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5395: @*/
    5396: PetscErrorCode DMGetBasicAdjacency(DM dm, PetscBool *useCone, PetscBool *useClosure)
    5397: {
    5398:   PetscInt Nf;

    5400:   PetscFunctionBegin;
    5402:   if (useCone) PetscAssertPointer(useCone, 2);
    5403:   if (useClosure) PetscAssertPointer(useClosure, 3);
    5404:   PetscCall(DMGetNumFields(dm, &Nf));
    5405:   if (!Nf) {
    5406:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5407:   } else {
    5408:     PetscCall(DMGetAdjacency(dm, 0, useCone, useClosure));
    5409:   }
    5410:   PetscFunctionReturn(PETSC_SUCCESS);
    5411: }

    5413: /*@
    5414:   DMSetBasicAdjacency - Set the flags for determining variable influence, using either the default or field 0 if it is defined

    5416:   Not Collective

    5418:   Input Parameters:
    5419: + dm         - The `DM` object
    5420: . useCone    - Flag for variable influence starting with the cone operation
    5421: - useClosure - Flag for variable influence using transitive closure

    5423:   Level: developer

    5425:   Notes:
    5426: .vb
    5427:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5428:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5429:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5430: .ve

    5432: .seealso: [](ch_dmbase), `DM`, `DMGetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5433: @*/
    5434: PetscErrorCode DMSetBasicAdjacency(DM dm, PetscBool useCone, PetscBool useClosure)
    5435: {
    5436:   PetscInt Nf;

    5438:   PetscFunctionBegin;
    5440:   PetscCall(DMGetNumFields(dm, &Nf));
    5441:   if (!Nf) {
    5442:     PetscCall(DMSetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5443:   } else {
    5444:     PetscCall(DMSetAdjacency(dm, 0, useCone, useClosure));
    5445:   }
    5446:   PetscFunctionReturn(PETSC_SUCCESS);
    5447: }

    5449: PetscErrorCode DMCompleteBCLabels_Internal(DM dm)
    5450: {
    5451:   DM           plex;
    5452:   DMLabel     *labels, *glabels;
    5453:   const char **names;
    5454:   char        *sendNames, *recvNames;
    5455:   PetscInt     Nds, s, maxLabels = 0, maxLen = 0, gmaxLen, Nl = 0, gNl, l, gl, m;
    5456:   size_t       len;
    5457:   MPI_Comm     comm;
    5458:   PetscMPIInt  rank, size, p, *counts, *displs;

    5460:   PetscFunctionBegin;
    5461:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5462:   PetscCallMPI(MPI_Comm_size(comm, &size));
    5463:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    5464:   PetscCall(DMGetNumDS(dm, &Nds));
    5465:   for (s = 0; s < Nds; ++s) {
    5466:     PetscDS  dsBC;
    5467:     PetscInt numBd;

    5469:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5470:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5471:     maxLabels += numBd;
    5472:   }
    5473:   PetscCall(PetscCalloc1(maxLabels, &labels));
    5474:   /* Get list of labels to be completed */
    5475:   for (s = 0; s < Nds; ++s) {
    5476:     PetscDS  dsBC;
    5477:     PetscInt numBd, bd;

    5479:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5480:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5481:     for (bd = 0; bd < numBd; ++bd) {
    5482:       DMLabel      label;
    5483:       PetscInt     field;
    5484:       PetscObject  obj;
    5485:       PetscClassId id;

    5487:       PetscCall(PetscDSGetBoundary(dsBC, bd, NULL, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    5488:       PetscCall(DMGetField(dm, field, NULL, &obj));
    5489:       PetscCall(PetscObjectGetClassId(obj, &id));
    5490:       if (id != PETSCFE_CLASSID || !label) continue;
    5491:       for (l = 0; l < Nl; ++l)
    5492:         if (labels[l] == label) break;
    5493:       if (l == Nl) labels[Nl++] = label;
    5494:     }
    5495:   }
    5496:   /* Get label names */
    5497:   PetscCall(PetscMalloc1(Nl, &names));
    5498:   for (l = 0; l < Nl; ++l) PetscCall(PetscObjectGetName((PetscObject)labels[l], &names[l]));
    5499:   for (l = 0; l < Nl; ++l) {
    5500:     PetscCall(PetscStrlen(names[l], &len));
    5501:     maxLen = PetscMax(maxLen, (PetscInt)len + 2);
    5502:   }
    5503:   PetscCall(PetscFree(labels));
    5504:   PetscCallMPI(MPIU_Allreduce(&maxLen, &gmaxLen, 1, MPIU_INT, MPI_MAX, comm));
    5505:   PetscCall(PetscCalloc1(Nl * gmaxLen, &sendNames));
    5506:   for (l = 0; l < Nl; ++l) PetscCall(PetscStrncpy(&sendNames[gmaxLen * l], names[l], gmaxLen));
    5507:   PetscCall(PetscFree(names));
    5508:   /* Put all names on all processes */
    5509:   PetscCall(PetscCalloc2(size, &counts, size + 1, &displs));
    5510:   PetscCallMPI(MPI_Allgather(&Nl, 1, MPI_INT, counts, 1, MPI_INT, comm));
    5511:   for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + counts[p];
    5512:   gNl = displs[size];
    5513:   for (p = 0; p < size; ++p) {
    5514:     counts[p] *= gmaxLen;
    5515:     displs[p] *= gmaxLen;
    5516:   }
    5517:   PetscCall(PetscCalloc2(gNl * gmaxLen, &recvNames, gNl, &glabels));
    5518:   PetscCallMPI(MPI_Allgatherv(sendNames, counts[rank], MPI_CHAR, recvNames, counts, displs, MPI_CHAR, comm));
    5519:   PetscCall(PetscFree2(counts, displs));
    5520:   PetscCall(PetscFree(sendNames));
    5521:   for (l = 0, gl = 0; l < gNl; ++l) {
    5522:     PetscCall(DMGetLabel(dm, &recvNames[l * gmaxLen], &glabels[gl]));
    5523:     PetscCheck(glabels[gl], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Label %s missing on rank %d", &recvNames[l * gmaxLen], rank);
    5524:     for (m = 0; m < gl; ++m)
    5525:       if (glabels[m] == glabels[gl]) goto next_label;
    5526:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    5527:     PetscCall(DMPlexLabelComplete(plex, glabels[gl]));
    5528:     PetscCall(DMDestroy(&plex));
    5529:     ++gl;
    5530:   next_label:
    5531:     continue;
    5532:   }
    5533:   PetscCall(PetscFree2(recvNames, glabels));
    5534:   PetscFunctionReturn(PETSC_SUCCESS);
    5535: }

    5537: static PetscErrorCode DMDSEnlarge_Static(DM dm, PetscInt NdsNew)
    5538: {
    5539:   DMSpace *tmpd;
    5540:   PetscInt Nds = dm->Nds, s;

    5542:   PetscFunctionBegin;
    5543:   if (Nds >= NdsNew) PetscFunctionReturn(PETSC_SUCCESS);
    5544:   PetscCall(PetscMalloc1(NdsNew, &tmpd));
    5545:   for (s = 0; s < Nds; ++s) tmpd[s] = dm->probs[s];
    5546:   for (s = Nds; s < NdsNew; ++s) {
    5547:     tmpd[s].ds     = NULL;
    5548:     tmpd[s].label  = NULL;
    5549:     tmpd[s].fields = NULL;
    5550:   }
    5551:   PetscCall(PetscFree(dm->probs));
    5552:   dm->Nds   = NdsNew;
    5553:   dm->probs = tmpd;
    5554:   PetscFunctionReturn(PETSC_SUCCESS);
    5555: }

    5557: /*@
    5558:   DMGetNumDS - Get the number of discrete systems in the `DM`

    5560:   Not Collective

    5562:   Input Parameter:
    5563: . dm - The `DM`

    5565:   Output Parameter:
    5566: . Nds - The number of `PetscDS` objects

    5568:   Level: intermediate

    5570: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMGetCellDS()`
    5571: @*/
    5572: PetscErrorCode DMGetNumDS(DM dm, PetscInt *Nds)
    5573: {
    5574:   PetscFunctionBegin;
    5576:   PetscAssertPointer(Nds, 2);
    5577:   *Nds = dm->Nds;
    5578:   PetscFunctionReturn(PETSC_SUCCESS);
    5579: }

    5581: /*@
    5582:   DMClearDS - Remove all discrete systems from the `DM`

    5584:   Logically Collective

    5586:   Input Parameter:
    5587: . dm - The `DM`

    5589:   Level: intermediate

    5591: .seealso: [](ch_dmbase), `DM`, `DMGetNumDS()`, `DMGetDS()`, `DMSetField()`
    5592: @*/
    5593: PetscErrorCode DMClearDS(DM dm)
    5594: {
    5595:   PetscInt s;

    5597:   PetscFunctionBegin;
    5599:   for (s = 0; s < dm->Nds; ++s) {
    5600:     PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5601:     PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5602:     PetscCall(DMLabelDestroy(&dm->probs[s].label));
    5603:     PetscCall(ISDestroy(&dm->probs[s].fields));
    5604:   }
    5605:   PetscCall(PetscFree(dm->probs));
    5606:   dm->probs = NULL;
    5607:   dm->Nds   = 0;
    5608:   PetscFunctionReturn(PETSC_SUCCESS);
    5609: }

    5611: /*@
    5612:   DMGetDS - Get the default `PetscDS`

    5614:   Not Collective

    5616:   Input Parameter:
    5617: . dm - The `DM`

    5619:   Output Parameter:
    5620: . ds - The default `PetscDS`

    5622:   Level: intermediate

    5624:   Note:
    5625:   The `ds` is owned by the `dm` and should not be destroyed directly.

    5627: .seealso: [](ch_dmbase), `DM`, `DMGetCellDS()`, `DMGetRegionDS()`
    5628: @*/
    5629: PetscErrorCode DMGetDS(DM dm, PetscDS *ds)
    5630: {
    5631:   PetscFunctionBeginHot;
    5633:   PetscAssertPointer(ds, 2);
    5634:   PetscCheck(dm->Nds > 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Need to call DMCreateDS() before calling DMGetDS()");
    5635:   *ds = dm->probs[0].ds;
    5636:   PetscFunctionReturn(PETSC_SUCCESS);
    5637: }

    5639: /*@
    5640:   DMGetCellDS - Get the `PetscDS` defined on a given cell

    5642:   Not Collective

    5644:   Input Parameters:
    5645: + dm    - The `DM`
    5646: - point - Cell for the `PetscDS`

    5648:   Output Parameters:
    5649: + ds   - The `PetscDS` defined on the given cell
    5650: - dsIn - The `PetscDS` for input on the given cell, or `NULL` if the same ds

    5652:   Level: developer

    5654: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMSetRegionDS()`
    5655: @*/
    5656: PetscErrorCode DMGetCellDS(DM dm, PetscInt point, PetscDS *ds, PetscDS *dsIn)
    5657: {
    5658:   PetscDS  dsDef = NULL;
    5659:   PetscInt s;

    5661:   PetscFunctionBeginHot;
    5663:   if (ds) PetscAssertPointer(ds, 3);
    5664:   if (dsIn) PetscAssertPointer(dsIn, 4);
    5665:   PetscCheck(point >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Mesh point cannot be negative: %" PetscInt_FMT, point);
    5666:   if (ds) *ds = NULL;
    5667:   if (dsIn) *dsIn = NULL;
    5668:   for (s = 0; s < dm->Nds; ++s) {
    5669:     PetscInt val;

    5671:     if (!dm->probs[s].label) {
    5672:       dsDef = dm->probs[s].ds;
    5673:     } else {
    5674:       PetscCall(DMLabelGetValue(dm->probs[s].label, point, &val));
    5675:       if (val >= 0) {
    5676:         if (ds) *ds = dm->probs[s].ds;
    5677:         if (dsIn) *dsIn = dm->probs[s].dsIn;
    5678:         break;
    5679:       }
    5680:     }
    5681:   }
    5682:   if (ds && !*ds) *ds = dsDef;
    5683:   PetscFunctionReturn(PETSC_SUCCESS);
    5684: }

    5686: /*@
    5687:   DMGetRegionDS - Get the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5689:   Not Collective

    5691:   Input Parameters:
    5692: + dm    - The `DM`
    5693: - label - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh

    5695:   Output Parameters:
    5696: + fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5697: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5698: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5700:   Level: advanced

    5702:   Note:
    5703:   If a non-`NULL` label is given, but there is no `PetscDS` on that specific label,
    5704:   the `PetscDS` for the full domain (if present) is returned. Returns with
    5705:   fields = `NULL` and ds = `NULL` if there is no `PetscDS` for the full domain.

    5707: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5708: @*/
    5709: PetscErrorCode DMGetRegionDS(DM dm, DMLabel label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5710: {
    5711:   PetscInt Nds = dm->Nds, s;

    5713:   PetscFunctionBegin;
    5716:   if (fields) {
    5717:     PetscAssertPointer(fields, 3);
    5718:     *fields = NULL;
    5719:   }
    5720:   if (ds) {
    5721:     PetscAssertPointer(ds, 4);
    5722:     *ds = NULL;
    5723:   }
    5724:   if (dsIn) {
    5725:     PetscAssertPointer(dsIn, 5);
    5726:     *dsIn = NULL;
    5727:   }
    5728:   for (s = 0; s < Nds; ++s) {
    5729:     if (dm->probs[s].label == label || !dm->probs[s].label) {
    5730:       if (fields) *fields = dm->probs[s].fields;
    5731:       if (ds) *ds = dm->probs[s].ds;
    5732:       if (dsIn) *dsIn = dm->probs[s].dsIn;
    5733:       if (dm->probs[s].label) PetscFunctionReturn(PETSC_SUCCESS);
    5734:     }
    5735:   }
    5736:   PetscFunctionReturn(PETSC_SUCCESS);
    5737: }

    5739: /*@
    5740:   DMSetRegionDS - Set the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5742:   Collective

    5744:   Input Parameters:
    5745: + dm     - The `DM`
    5746: . label  - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh
    5747: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` for all fields
    5748: . ds     - The `PetscDS` defined on the given region
    5749: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5751:   Level: advanced

    5753:   Note:
    5754:   If the label has a `PetscDS` defined, it will be replaced. Otherwise, it will be added to the `DM`. If the `PetscDS` is replaced,
    5755:   the fields argument is ignored.

    5757: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionNumDS()`, `DMGetDS()`, `DMGetCellDS()`
    5758: @*/
    5759: PetscErrorCode DMSetRegionDS(DM dm, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5760: {
    5761:   PetscInt Nds = dm->Nds, s;

    5763:   PetscFunctionBegin;
    5769:   for (s = 0; s < Nds; ++s) {
    5770:     if (dm->probs[s].label == label) {
    5771:       PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5772:       PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5773:       dm->probs[s].ds   = ds;
    5774:       dm->probs[s].dsIn = dsIn;
    5775:       PetscFunctionReturn(PETSC_SUCCESS);
    5776:     }
    5777:   }
    5778:   PetscCall(DMDSEnlarge_Static(dm, Nds + 1));
    5779:   PetscCall(PetscObjectReference((PetscObject)label));
    5780:   PetscCall(PetscObjectReference((PetscObject)fields));
    5781:   PetscCall(PetscObjectReference((PetscObject)ds));
    5782:   PetscCall(PetscObjectReference((PetscObject)dsIn));
    5783:   if (!label) {
    5784:     /* Put the NULL label at the front, so it is returned as the default */
    5785:     for (s = Nds - 1; s >= 0; --s) dm->probs[s + 1] = dm->probs[s];
    5786:     Nds = 0;
    5787:   }
    5788:   dm->probs[Nds].label  = label;
    5789:   dm->probs[Nds].fields = fields;
    5790:   dm->probs[Nds].ds     = ds;
    5791:   dm->probs[Nds].dsIn   = dsIn;
    5792:   PetscFunctionReturn(PETSC_SUCCESS);
    5793: }

    5795: /*@
    5796:   DMGetRegionNumDS - Get the `PetscDS` for a given mesh region, defined by the region number

    5798:   Not Collective

    5800:   Input Parameters:
    5801: + dm  - The `DM`
    5802: - num - The region number, in [0, Nds)

    5804:   Output Parameters:
    5805: + label  - The region label, or `NULL`
    5806: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5807: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5808: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5810:   Level: advanced

    5812: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5813: @*/
    5814: PetscErrorCode DMGetRegionNumDS(DM dm, PetscInt num, DMLabel *label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5815: {
    5816:   PetscInt Nds;

    5818:   PetscFunctionBegin;
    5820:   PetscCall(DMGetNumDS(dm, &Nds));
    5821:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5822:   if (label) {
    5823:     PetscAssertPointer(label, 3);
    5824:     *label = dm->probs[num].label;
    5825:   }
    5826:   if (fields) {
    5827:     PetscAssertPointer(fields, 4);
    5828:     *fields = dm->probs[num].fields;
    5829:   }
    5830:   if (ds) {
    5831:     PetscAssertPointer(ds, 5);
    5832:     *ds = dm->probs[num].ds;
    5833:   }
    5834:   if (dsIn) {
    5835:     PetscAssertPointer(dsIn, 6);
    5836:     *dsIn = dm->probs[num].dsIn;
    5837:   }
    5838:   PetscFunctionReturn(PETSC_SUCCESS);
    5839: }

    5841: /*@
    5842:   DMSetRegionNumDS - Set the `PetscDS` for a given mesh region, defined by the region number

    5844:   Not Collective

    5846:   Input Parameters:
    5847: + dm     - The `DM`
    5848: . num    - The region number, in [0, Nds)
    5849: . label  - The region label, or `NULL`
    5850: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` to prevent setting
    5851: . ds     - The `PetscDS` defined on the given region, or `NULL` to prevent setting
    5852: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5854:   Level: advanced

    5856: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5857: @*/
    5858: PetscErrorCode DMSetRegionNumDS(DM dm, PetscInt num, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5859: {
    5860:   PetscInt Nds;

    5862:   PetscFunctionBegin;
    5865:   PetscCall(DMGetNumDS(dm, &Nds));
    5866:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5867:   PetscCall(PetscObjectReference((PetscObject)label));
    5868:   PetscCall(DMLabelDestroy(&dm->probs[num].label));
    5869:   dm->probs[num].label = label;
    5870:   if (fields) {
    5872:     PetscCall(PetscObjectReference((PetscObject)fields));
    5873:     PetscCall(ISDestroy(&dm->probs[num].fields));
    5874:     dm->probs[num].fields = fields;
    5875:   }
    5876:   if (ds) {
    5878:     PetscCall(PetscObjectReference((PetscObject)ds));
    5879:     PetscCall(PetscDSDestroy(&dm->probs[num].ds));
    5880:     dm->probs[num].ds = ds;
    5881:   }
    5882:   if (dsIn) {
    5884:     PetscCall(PetscObjectReference((PetscObject)dsIn));
    5885:     PetscCall(PetscDSDestroy(&dm->probs[num].dsIn));
    5886:     dm->probs[num].dsIn = dsIn;
    5887:   }
    5888:   PetscFunctionReturn(PETSC_SUCCESS);
    5889: }

    5891: /*@
    5892:   DMFindRegionNum - Find the region number for a given `PetscDS`, or -1 if it is not found.

    5894:   Not Collective

    5896:   Input Parameters:
    5897: + dm - The `DM`
    5898: - ds - The `PetscDS` defined on the given region

    5900:   Output Parameter:
    5901: . num - The region number, in [0, Nds), or -1 if not found

    5903:   Level: advanced

    5905: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5906: @*/
    5907: PetscErrorCode DMFindRegionNum(DM dm, PetscDS ds, PetscInt *num)
    5908: {
    5909:   PetscInt Nds, n;

    5911:   PetscFunctionBegin;
    5914:   PetscAssertPointer(num, 3);
    5915:   PetscCall(DMGetNumDS(dm, &Nds));
    5916:   for (n = 0; n < Nds; ++n)
    5917:     if (ds == dm->probs[n].ds) break;
    5918:   if (n >= Nds) *num = -1;
    5919:   else *num = n;
    5920:   PetscFunctionReturn(PETSC_SUCCESS);
    5921: }

    5923: /*@
    5924:   DMCreateFEDefault - Create a `PetscFE` based on the celltype for the mesh

    5926:   Not Collective

    5928:   Input Parameters:
    5929: + dm     - The `DM`
    5930: . Nc     - The number of components for the field
    5931: . prefix - The options prefix for the output `PetscFE`, or `NULL`
    5932: - qorder - The quadrature order or `PETSC_DETERMINE` to use `PetscSpace` polynomial degree

    5934:   Output Parameter:
    5935: . fem - The `PetscFE`

    5937:   Level: intermediate

    5939:   Note:
    5940:   This is a convenience method that just calls `PetscFECreateByCell()` underneath.

    5942: .seealso: [](ch_dmbase), `DM`, `PetscFECreateByCell()`, `DMAddField()`, `DMCreateDS()`, `DMGetCellDS()`, `DMGetRegionDS()`
    5943: @*/
    5944: PetscErrorCode DMCreateFEDefault(DM dm, PetscInt Nc, const char prefix[], PetscInt qorder, PetscFE *fem)
    5945: {
    5946:   DMPolytopeType ct;
    5947:   PetscInt       dim, cStart;

    5949:   PetscFunctionBegin;
    5952:   if (prefix) PetscAssertPointer(prefix, 3);
    5954:   PetscAssertPointer(fem, 5);
    5955:   PetscCall(DMGetDimension(dm, &dim));
    5956:   PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    5957:   PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    5958:   PetscCall(PetscFECreateByCell(PETSC_COMM_SELF, dim, Nc, ct, prefix, qorder, fem));
    5959:   PetscFunctionReturn(PETSC_SUCCESS);
    5960: }

    5962: /*@
    5963:   DMCreateDS - Create the discrete systems for the `DM` based upon the fields added to the `DM`

    5965:   Collective

    5967:   Input Parameter:
    5968: . dm - The `DM`

    5970:   Options Database Key:
    5971: . -dm_petscds_view - View all the `PetscDS` objects in this `DM`

    5973:   Level: intermediate

    5975:   Developer Note:
    5976:   The name of this function is wrong. Create functions always return the created object as one of the arguments.

    5978: .seealso: [](ch_dmbase), `DM`, `DMSetField`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    5979: @*/
    5980: PetscErrorCode DMCreateDS(DM dm)
    5981: {
    5982:   MPI_Comm  comm;
    5983:   PetscDS   dsDef;
    5984:   DMLabel  *labelSet;
    5985:   PetscInt  dE, Nf = dm->Nf, f, s, Nl, l, Ndef, k;
    5986:   PetscBool doSetup = PETSC_TRUE, flg;

    5988:   PetscFunctionBegin;
    5990:   if (!dm->fields) PetscFunctionReturn(PETSC_SUCCESS);
    5991:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5992:   PetscCall(DMGetCoordinateDim(dm, &dE));
    5993:   // Create nullspace constructor slots
    5994:   PetscCall(PetscFree2(dm->nullspaceConstructors, dm->nearnullspaceConstructors));
    5995:   PetscCall(PetscCalloc2(Nf, &dm->nullspaceConstructors, Nf, &dm->nearnullspaceConstructors));
    5996:   /* Determine how many regions we have */
    5997:   PetscCall(PetscMalloc1(Nf, &labelSet));
    5998:   Nl   = 0;
    5999:   Ndef = 0;
    6000:   for (f = 0; f < Nf; ++f) {
    6001:     DMLabel  label = dm->fields[f].label;
    6002:     PetscInt l;

    6004: #ifdef PETSC_HAVE_LIBCEED
    6005:     /* Move CEED context to discretizations */
    6006:     {
    6007:       PetscClassId id;

    6009:       PetscCall(PetscObjectGetClassId(dm->fields[f].disc, &id));
    6010:       if (id == PETSCFE_CLASSID) {
    6011:         Ceed ceed;

    6013:         PetscCall(DMGetCeed(dm, &ceed));
    6014:         PetscCall(PetscFESetCeed((PetscFE)dm->fields[f].disc, ceed));
    6015:       }
    6016:     }
    6017: #endif
    6018:     if (!label) {
    6019:       ++Ndef;
    6020:       continue;
    6021:     }
    6022:     for (l = 0; l < Nl; ++l)
    6023:       if (label == labelSet[l]) break;
    6024:     if (l < Nl) continue;
    6025:     labelSet[Nl++] = label;
    6026:   }
    6027:   /* Create default DS if there are no labels to intersect with */
    6028:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    6029:   if (!dsDef && Ndef && !Nl) {
    6030:     IS        fields;
    6031:     PetscInt *fld, nf;

    6033:     for (f = 0, nf = 0; f < Nf; ++f)
    6034:       if (!dm->fields[f].label) ++nf;
    6035:     PetscCheck(nf, comm, PETSC_ERR_PLIB, "All fields have labels, but we are trying to create a default DS");
    6036:     PetscCall(PetscMalloc1(nf, &fld));
    6037:     for (f = 0, nf = 0; f < Nf; ++f)
    6038:       if (!dm->fields[f].label) fld[nf++] = f;
    6039:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    6040:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    6041:     PetscCall(ISSetType(fields, ISGENERAL));
    6042:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));

    6044:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    6045:     PetscCall(DMSetRegionDS(dm, NULL, fields, dsDef, NULL));
    6046:     PetscCall(PetscDSDestroy(&dsDef));
    6047:     PetscCall(ISDestroy(&fields));
    6048:   }
    6049:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    6050:   if (dsDef) PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    6051:   /* Intersect labels with default fields */
    6052:   if (Ndef && Nl) {
    6053:     DM              plex;
    6054:     DMLabel         cellLabel;
    6055:     IS              fieldIS, allcellIS, defcellIS = NULL;
    6056:     PetscInt       *fields;
    6057:     const PetscInt *cells;
    6058:     PetscInt        depth, nf = 0, n, c;

    6060:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    6061:     PetscCall(DMPlexGetDepth(plex, &depth));
    6062:     PetscCall(DMGetStratumIS(plex, "dim", depth, &allcellIS));
    6063:     if (!allcellIS) PetscCall(DMGetStratumIS(plex, "depth", depth, &allcellIS));
    6064:     /* TODO This looks like it only works for one label */
    6065:     for (l = 0; l < Nl; ++l) {
    6066:       DMLabel label = labelSet[l];
    6067:       IS      pointIS;

    6069:       PetscCall(ISDestroy(&defcellIS));
    6070:       PetscCall(DMLabelGetStratumIS(label, 1, &pointIS));
    6071:       PetscCall(ISDifference(allcellIS, pointIS, &defcellIS));
    6072:       PetscCall(ISDestroy(&pointIS));
    6073:     }
    6074:     PetscCall(ISDestroy(&allcellIS));

    6076:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, "defaultCells", &cellLabel));
    6077:     PetscCall(ISGetLocalSize(defcellIS, &n));
    6078:     PetscCall(ISGetIndices(defcellIS, &cells));
    6079:     for (c = 0; c < n; ++c) PetscCall(DMLabelSetValue(cellLabel, cells[c], 1));
    6080:     PetscCall(ISRestoreIndices(defcellIS, &cells));
    6081:     PetscCall(ISDestroy(&defcellIS));
    6082:     PetscCall(DMPlexLabelComplete(plex, cellLabel));

    6084:     PetscCall(PetscMalloc1(Ndef, &fields));
    6085:     for (f = 0; f < Nf; ++f)
    6086:       if (!dm->fields[f].label) fields[nf++] = f;
    6087:     PetscCall(ISCreate(PETSC_COMM_SELF, &fieldIS));
    6088:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fieldIS, "dm_fields_"));
    6089:     PetscCall(ISSetType(fieldIS, ISGENERAL));
    6090:     PetscCall(ISGeneralSetIndices(fieldIS, nf, fields, PETSC_OWN_POINTER));

    6092:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    6093:     PetscCall(DMSetRegionDS(dm, cellLabel, fieldIS, dsDef, NULL));
    6094:     PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    6095:     PetscCall(DMLabelDestroy(&cellLabel));
    6096:     PetscCall(PetscDSDestroy(&dsDef));
    6097:     PetscCall(ISDestroy(&fieldIS));
    6098:     PetscCall(DMDestroy(&plex));
    6099:   }
    6100:   /* Create label DSes
    6101:      - WE ONLY SUPPORT IDENTICAL OR DISJOINT LABELS
    6102:   */
    6103:   /* TODO Should check that labels are disjoint */
    6104:   for (l = 0; l < Nl; ++l) {
    6105:     DMLabel   label = labelSet[l];
    6106:     PetscDS   ds, dsIn = NULL;
    6107:     IS        fields;
    6108:     PetscInt *fld, nf;

    6110:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
    6111:     for (f = 0, nf = 0; f < Nf; ++f)
    6112:       if (label == dm->fields[f].label || !dm->fields[f].label) ++nf;
    6113:     PetscCall(PetscMalloc1(nf, &fld));
    6114:     for (f = 0, nf = 0; f < Nf; ++f)
    6115:       if (label == dm->fields[f].label || !dm->fields[f].label) fld[nf++] = f;
    6116:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    6117:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    6118:     PetscCall(ISSetType(fields, ISGENERAL));
    6119:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));
    6120:     PetscCall(PetscDSSetCoordinateDimension(ds, dE));
    6121:     {
    6122:       DMPolytopeType ct;
    6123:       PetscInt       lStart, lEnd;
    6124:       PetscBool      isCohesiveLocal = PETSC_FALSE, isCohesive;

    6126:       PetscCall(DMLabelGetBounds(label, &lStart, &lEnd));
    6127:       if (lStart >= 0) {
    6128:         PetscCall(DMPlexGetCellType(dm, lStart, &ct));
    6129:         switch (ct) {
    6130:         case DM_POLYTOPE_POINT_PRISM_TENSOR:
    6131:         case DM_POLYTOPE_SEG_PRISM_TENSOR:
    6132:         case DM_POLYTOPE_TRI_PRISM_TENSOR:
    6133:         case DM_POLYTOPE_QUAD_PRISM_TENSOR:
    6134:           isCohesiveLocal = PETSC_TRUE;
    6135:           break;
    6136:         default:
    6137:           break;
    6138:         }
    6139:       }
    6140:       PetscCallMPI(MPIU_Allreduce(&isCohesiveLocal, &isCohesive, 1, MPI_C_BOOL, MPI_LOR, comm));
    6141:       if (isCohesive) {
    6142:         PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsIn));
    6143:         PetscCall(PetscDSSetCoordinateDimension(dsIn, dE));
    6144:       }
    6145:       for (f = 0, nf = 0; f < Nf; ++f) {
    6146:         if (label == dm->fields[f].label || !dm->fields[f].label) {
    6147:           if (label == dm->fields[f].label) {
    6148:             PetscCall(PetscDSSetDiscretization(ds, nf, NULL));
    6149:             PetscCall(PetscDSSetCohesive(ds, nf, isCohesive));
    6150:             if (dsIn) {
    6151:               PetscCall(PetscDSSetDiscretization(dsIn, nf, NULL));
    6152:               PetscCall(PetscDSSetCohesive(dsIn, nf, isCohesive));
    6153:             }
    6154:           }
    6155:           ++nf;
    6156:         }
    6157:       }
    6158:     }
    6159:     PetscCall(DMSetRegionDS(dm, label, fields, ds, dsIn));
    6160:     PetscCall(ISDestroy(&fields));
    6161:     PetscCall(PetscDSDestroy(&ds));
    6162:     PetscCall(PetscDSDestroy(&dsIn));
    6163:   }
    6164:   PetscCall(PetscFree(labelSet));
    6165:   /* Set fields in DSes */
    6166:   for (s = 0; s < dm->Nds; ++s) {
    6167:     PetscDS         ds     = dm->probs[s].ds;
    6168:     PetscDS         dsIn   = dm->probs[s].dsIn;
    6169:     IS              fields = dm->probs[s].fields;
    6170:     const PetscInt *fld;
    6171:     PetscInt        nf, dsnf;
    6172:     PetscBool       isCohesive;

    6174:     PetscCall(PetscDSGetNumFields(ds, &dsnf));
    6175:     PetscCall(PetscDSIsCohesive(ds, &isCohesive));
    6176:     PetscCall(ISGetLocalSize(fields, &nf));
    6177:     PetscCall(ISGetIndices(fields, &fld));
    6178:     for (f = 0; f < nf; ++f) {
    6179:       PetscObject  disc = dm->fields[fld[f]].disc;
    6180:       PetscBool    isCohesiveField;
    6181:       PetscClassId id;

    6183:       /* Handle DS with no fields */
    6184:       if (dsnf) PetscCall(PetscDSGetCohesive(ds, f, &isCohesiveField));
    6185:       /* If this is a cohesive cell, then regular fields need the lower dimensional discretization */
    6186:       if (isCohesive) {
    6187:         if (!isCohesiveField) {
    6188:           PetscObject bdDisc;

    6190:           PetscCall(PetscFEGetHeightSubspace((PetscFE)disc, 1, (PetscFE *)&bdDisc));
    6191:           PetscCall(PetscDSSetDiscretization(ds, f, bdDisc));
    6192:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6193:         } else {
    6194:           PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6195:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6196:         }
    6197:       } else {
    6198:         PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6199:       }
    6200:       /* We allow people to have placeholder fields and construct the Section by hand */
    6201:       PetscCall(PetscObjectGetClassId(disc, &id));
    6202:       if ((id != PETSCFE_CLASSID) && (id != PETSCFV_CLASSID)) doSetup = PETSC_FALSE;
    6203:     }
    6204:     PetscCall(ISRestoreIndices(fields, &fld));
    6205:   }
    6206:   /* Allow k-jet tabulation */
    6207:   PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)dm)->prefix, "-dm_ds_jet_degree", &k, &flg));
    6208:   if (flg) {
    6209:     for (s = 0; s < dm->Nds; ++s) {
    6210:       PetscDS  ds   = dm->probs[s].ds;
    6211:       PetscDS  dsIn = dm->probs[s].dsIn;
    6212:       PetscInt Nf, f;

    6214:       PetscCall(PetscDSGetNumFields(ds, &Nf));
    6215:       for (f = 0; f < Nf; ++f) {
    6216:         PetscCall(PetscDSSetJetDegree(ds, f, k));
    6217:         if (dsIn) PetscCall(PetscDSSetJetDegree(dsIn, f, k));
    6218:       }
    6219:     }
    6220:   }
    6221:   /* Setup DSes */
    6222:   if (doSetup) {
    6223:     for (s = 0; s < dm->Nds; ++s) {
    6224:       if (dm->setfromoptionscalled) {
    6225:         PetscCall(PetscDSSetFromOptions(dm->probs[s].ds));
    6226:         if (dm->probs[s].dsIn) PetscCall(PetscDSSetFromOptions(dm->probs[s].dsIn));
    6227:       }
    6228:       PetscCall(PetscDSSetUp(dm->probs[s].ds));
    6229:       if (dm->probs[s].dsIn) PetscCall(PetscDSSetUp(dm->probs[s].dsIn));
    6230:     }
    6231:   }
    6232:   PetscFunctionReturn(PETSC_SUCCESS);
    6233: }

    6235: /*@
    6236:   DMUseTensorOrder - Use a tensor product closure ordering for the default section

    6238:   Input Parameters:
    6239: + dm     - The DM
    6240: - tensor - Flag for tensor order

    6242:   Level: developer

    6244: .seealso: `DMPlexSetClosurePermutationTensor()`, `PetscSectionResetClosurePermutation()`
    6245: @*/
    6246: PetscErrorCode DMUseTensorOrder(DM dm, PetscBool tensor)
    6247: {
    6248:   PetscInt  Nf;
    6249:   PetscBool reorder = PETSC_TRUE, isPlex;

    6251:   PetscFunctionBegin;
    6252:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, DMPLEX, &isPlex));
    6253:   PetscCall(DMGetNumFields(dm, &Nf));
    6254:   for (PetscInt f = 0; f < Nf; ++f) {
    6255:     PetscObject  obj;
    6256:     PetscClassId id;

    6258:     PetscCall(DMGetField(dm, f, NULL, &obj));
    6259:     PetscCall(PetscObjectGetClassId(obj, &id));
    6260:     if (id == PETSCFE_CLASSID) {
    6261:       PetscSpace sp;
    6262:       PetscBool  tensor;

    6264:       PetscCall(PetscFEGetBasisSpace((PetscFE)obj, &sp));
    6265:       PetscCall(PetscSpacePolynomialGetTensor(sp, &tensor));
    6266:       reorder = reorder && tensor ? PETSC_TRUE : PETSC_FALSE;
    6267:     } else reorder = PETSC_FALSE;
    6268:   }
    6269:   if (tensor) {
    6270:     if (reorder && isPlex) PetscCall(DMPlexSetClosurePermutationTensor(dm, PETSC_DETERMINE, NULL));
    6271:   } else {
    6272:     PetscSection s;

    6274:     PetscCall(DMGetLocalSection(dm, &s));
    6275:     if (s) PetscCall(PetscSectionResetClosurePermutation(s));
    6276:   }
    6277:   PetscFunctionReturn(PETSC_SUCCESS);
    6278: }

    6280: /*@
    6281:   DMComputeExactSolution - Compute the exact solution for a given `DM`, using the `PetscDS` information.

    6283:   Collective

    6285:   Input Parameters:
    6286: + dm   - The `DM`
    6287: - time - The time

    6289:   Output Parameters:
    6290: + u   - The vector will be filled with exact solution values, or `NULL`
    6291: - u_t - The vector will be filled with the time derivative of exact solution values, or `NULL`

    6293:   Level: developer

    6295:   Note:
    6296:   The user must call `PetscDSSetExactSolution()` before using this routine

    6298: .seealso: [](ch_dmbase), `DM`, `PetscDSSetExactSolution()`
    6299: @*/
    6300: PetscErrorCode DMComputeExactSolution(DM dm, PetscReal time, Vec u, Vec u_t)
    6301: {
    6302:   PetscErrorCode (**exacts)(PetscInt, PetscReal, const PetscReal x[], PetscInt, PetscScalar *u, PetscCtx ctx);
    6303:   void   **ectxs;
    6304:   Vec      locu, locu_t;
    6305:   PetscInt Nf, Nds, s;

    6307:   PetscFunctionBegin;
    6309:   if (u) {
    6311:     PetscCall(DMGetLocalVector(dm, &locu));
    6312:     PetscCall(VecSet(locu, 0.));
    6313:   }
    6314:   if (u_t) {
    6316:     PetscCall(DMGetLocalVector(dm, &locu_t));
    6317:     PetscCall(VecSet(locu_t, 0.));
    6318:   }
    6319:   PetscCall(DMGetNumFields(dm, &Nf));
    6320:   PetscCall(PetscMalloc2(Nf, &exacts, Nf, &ectxs));
    6321:   PetscCall(DMGetNumDS(dm, &Nds));
    6322:   for (s = 0; s < Nds; ++s) {
    6323:     PetscDS         ds;
    6324:     DMLabel         label;
    6325:     IS              fieldIS;
    6326:     const PetscInt *fields, id = 1;
    6327:     PetscInt        dsNf, f;

    6329:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    6330:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    6331:     PetscCall(ISGetIndices(fieldIS, &fields));
    6332:     PetscCall(PetscArrayzero(exacts, Nf));
    6333:     PetscCall(PetscArrayzero(ectxs, Nf));
    6334:     if (u) {
    6335:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolution(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6336:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6337:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6338:     }
    6339:     if (u_t) {
    6340:       PetscCall(PetscArrayzero(exacts, Nf));
    6341:       PetscCall(PetscArrayzero(ectxs, Nf));
    6342:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolutionTimeDerivative(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6343:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6344:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6345:     }
    6346:     PetscCall(ISRestoreIndices(fieldIS, &fields));
    6347:   }
    6348:   if (u) {
    6349:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution"));
    6350:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u, "exact_"));
    6351:   }
    6352:   if (u_t) {
    6353:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution Time Derivative"));
    6354:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u_t, "exact_t_"));
    6355:   }
    6356:   PetscCall(PetscFree2(exacts, ectxs));
    6357:   if (u) {
    6358:     PetscCall(DMLocalToGlobalBegin(dm, locu, INSERT_ALL_VALUES, u));
    6359:     PetscCall(DMLocalToGlobalEnd(dm, locu, INSERT_ALL_VALUES, u));
    6360:     PetscCall(DMRestoreLocalVector(dm, &locu));
    6361:   }
    6362:   if (u_t) {
    6363:     PetscCall(DMLocalToGlobalBegin(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6364:     PetscCall(DMLocalToGlobalEnd(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6365:     PetscCall(DMRestoreLocalVector(dm, &locu_t));
    6366:   }
    6367:   PetscFunctionReturn(PETSC_SUCCESS);
    6368: }

    6370: static PetscErrorCode DMTransferDS_Internal(DM dm, DMLabel label, IS fields, PetscInt minDegree, PetscInt maxDegree, PetscDS ds, PetscDS dsIn)
    6371: {
    6372:   PetscDS dsNew, dsInNew = NULL;

    6374:   PetscFunctionBegin;
    6375:   PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)ds), &dsNew));
    6376:   PetscCall(PetscDSCopy(ds, minDegree, maxDegree, dm, dsNew));
    6377:   if (dsIn) {
    6378:     PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)dsIn), &dsInNew));
    6379:     PetscCall(PetscDSCopy(dsIn, minDegree, maxDegree, dm, dsInNew));
    6380:   }
    6381:   PetscCall(DMSetRegionDS(dm, label, fields, dsNew, dsInNew));
    6382:   PetscCall(PetscDSDestroy(&dsNew));
    6383:   PetscCall(PetscDSDestroy(&dsInNew));
    6384:   PetscFunctionReturn(PETSC_SUCCESS);
    6385: }

    6387: /*@
    6388:   DMCopyDS - Copy the discrete systems for the `DM` into another `DM`

    6390:   Collective

    6392:   Input Parameters:
    6393: + dm        - The `DM`
    6394: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    6395: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    6397:   Output Parameter:
    6398: . newdm - The `DM`

    6400:   Level: advanced

    6402: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    6403: @*/
    6404: PetscErrorCode DMCopyDS(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    6405: {
    6406:   PetscInt Nds, s;

    6408:   PetscFunctionBegin;
    6409:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    6410:   PetscCall(DMGetNumDS(dm, &Nds));
    6411:   PetscCall(DMClearDS(newdm));
    6412:   for (s = 0; s < Nds; ++s) {
    6413:     DMLabel  label;
    6414:     IS       fields;
    6415:     PetscDS  ds, dsIn, newds;
    6416:     PetscInt Nbd, bd;

    6418:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fields, &ds, &dsIn));
    6419:     /* TODO: We need to change all keys from labels in the old DM to labels in the new DM */
    6420:     PetscCall(DMTransferDS_Internal(newdm, label, fields, minDegree, maxDegree, ds, dsIn));
    6421:     /* Complete new labels in the new DS */
    6422:     PetscCall(DMGetRegionDS(newdm, label, NULL, &newds, NULL));
    6423:     PetscCall(PetscDSGetNumBoundary(newds, &Nbd));
    6424:     for (bd = 0; bd < Nbd; ++bd) {
    6425:       PetscWeakForm wf;
    6426:       DMLabel       label;
    6427:       PetscInt      field;

    6429:       PetscCall(PetscDSGetBoundary(newds, bd, &wf, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    6430:       PetscCall(PetscWeakFormReplaceLabel(wf, label));
    6431:     }
    6432:   }
    6433:   PetscCall(DMCompleteBCLabels_Internal(newdm));
    6434:   PetscFunctionReturn(PETSC_SUCCESS);
    6435: }

    6437: /*@
    6438:   DMCopyDisc - Copy the fields and discrete systems for the `DM` into another `DM`

    6440:   Collective

    6442:   Input Parameter:
    6443: . dm - The `DM`

    6445:   Output Parameter:
    6446: . newdm - The `DM`

    6448:   Level: advanced

    6450:   Developer Note:
    6451:   Really ugly name, nothing in PETSc is called a `Disc` plus it is an ugly abbreviation

    6453: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMCopyDS()`
    6454: @*/
    6455: PetscErrorCode DMCopyDisc(DM dm, DM newdm)
    6456: {
    6457:   PetscFunctionBegin;
    6458:   PetscCall(DMCopyFields(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6459:   PetscCall(DMCopyDS(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6460:   PetscFunctionReturn(PETSC_SUCCESS);
    6461: }

    6463: /*@
    6464:   DMGetDimension - Return the topological dimension of the `DM`

    6466:   Not Collective

    6468:   Input Parameter:
    6469: . dm - The `DM`

    6471:   Output Parameter:
    6472: . dim - The topological dimension

    6474:   Level: beginner

    6476: .seealso: [](ch_dmbase), `DM`, `DMSetDimension()`, `DMCreate()`
    6477: @*/
    6478: PetscErrorCode DMGetDimension(DM dm, PetscInt *dim)
    6479: {
    6480:   PetscFunctionBegin;
    6482:   PetscAssertPointer(dim, 2);
    6483:   *dim = dm->dim;
    6484:   PetscFunctionReturn(PETSC_SUCCESS);
    6485: }

    6487: /*@
    6488:   DMSetDimension - Set the topological dimension of the `DM`

    6490:   Collective

    6492:   Input Parameters:
    6493: + dm  - The `DM`
    6494: - dim - The topological dimension

    6496:   Level: beginner

    6498: .seealso: [](ch_dmbase), `DM`, `DMGetDimension()`, `DMCreate()`
    6499: @*/
    6500: PetscErrorCode DMSetDimension(DM dm, PetscInt dim)
    6501: {
    6502:   PetscDS  ds;
    6503:   PetscInt Nds, n;

    6505:   PetscFunctionBegin;
    6508:   if (dm->dim != dim) PetscCall(DMSetPeriodicity(dm, NULL, NULL, NULL));
    6509:   dm->dim = dim;
    6510:   if (dm->dim >= 0) {
    6511:     PetscCall(DMGetNumDS(dm, &Nds));
    6512:     for (n = 0; n < Nds; ++n) {
    6513:       PetscCall(DMGetRegionNumDS(dm, n, NULL, NULL, &ds, NULL));
    6514:       if (ds->dimEmbed < 0) PetscCall(PetscDSSetCoordinateDimension(ds, dim));
    6515:     }
    6516:   }
    6517:   PetscFunctionReturn(PETSC_SUCCESS);
    6518: }

    6520: /*@
    6521:   DMGetDimPoints - Get the half-open interval for all points of a given dimension

    6523:   Collective

    6525:   Input Parameters:
    6526: + dm  - the `DM`
    6527: - dim - the dimension

    6529:   Output Parameters:
    6530: + pStart - The first point of the given dimension
    6531: - pEnd   - The first point following points of the given dimension

    6533:   Level: intermediate

    6535:   Note:
    6536:   The points are vertices in the Hasse diagram encoding the topology. This is explained in
    6537:   https://arxiv.org/abs/0908.4427. If no points exist of this dimension in the storage scheme,
    6538:   then the interval is empty.

    6540: .seealso: [](ch_dmbase), `DM`, `DMPLEX`, `DMPlexGetDepthStratum()`, `DMPlexGetHeightStratum()`
    6541: @*/
    6542: PetscErrorCode DMGetDimPoints(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
    6543: {
    6544:   PetscInt d;

    6546:   PetscFunctionBegin;
    6548:   PetscCall(DMGetDimension(dm, &d));
    6549:   PetscCheck((dim >= 0) && (dim <= d), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid dimension %" PetscInt_FMT, dim);
    6550:   PetscUseTypeMethod(dm, getdimpoints, dim, pStart, pEnd);
    6551:   PetscFunctionReturn(PETSC_SUCCESS);
    6552: }

    6554: /*@
    6555:   DMGetOutputDM - Retrieve the `DM` associated with the layout for output

    6557:   Collective

    6559:   Input Parameter:
    6560: . dm - The original `DM`

    6562:   Output Parameter:
    6563: . odm - The `DM` which provides the layout for output

    6565:   Level: intermediate

    6567:   Note:
    6568:   In some situations the vector obtained with `DMCreateGlobalVector()` excludes points for degrees of freedom that are associated with fixed (Dirichelet) boundary
    6569:   conditions since the algebraic solver does not solve for those variables. The output `DM` includes these excluded points and its global vector contains the
    6570:   locations for those dof so that they can be output to a file or other viewer along with the unconstrained dof.

    6572: .seealso: [](ch_dmbase), `DM`, `VecView()`, `DMGetGlobalSection()`, `DMCreateGlobalVector()`, `PetscSectionHasConstraints()`, `DMSetGlobalSection()`
    6573: @*/
    6574: PetscErrorCode DMGetOutputDM(DM dm, DM *odm)
    6575: {
    6576:   PetscSection section;
    6577:   IS           perm;
    6578:   PetscBool    hasConstraints, newDM, gnewDM;
    6579:   PetscInt     num_face_sfs = 0;

    6581:   PetscFunctionBegin;
    6583:   PetscAssertPointer(odm, 2);
    6584:   PetscCall(DMGetLocalSection(dm, &section));
    6585:   PetscCall(PetscSectionHasConstraints(section, &hasConstraints));
    6586:   PetscCall(PetscSectionGetPermutation(section, &perm));
    6587:   PetscCall(DMPlexGetIsoperiodicFaceSF(dm, &num_face_sfs, NULL));
    6588:   newDM = hasConstraints || perm || (num_face_sfs > 0) ? PETSC_TRUE : PETSC_FALSE;
    6589:   PetscCallMPI(MPIU_Allreduce(&newDM, &gnewDM, 1, MPI_C_BOOL, MPI_LOR, PetscObjectComm((PetscObject)dm)));
    6590:   if (!gnewDM) {
    6591:     *odm = dm;
    6592:     PetscFunctionReturn(PETSC_SUCCESS);
    6593:   }
    6594:   if (!dm->dmBC) {
    6595:     PetscSection newSection, gsection;
    6596:     PetscSF      sf, sfNatural;
    6597:     PetscBool    usePerm = dm->ignorePermOutput ? PETSC_FALSE : PETSC_TRUE;

    6599:     PetscCall(DMClone(dm, &dm->dmBC));
    6600:     PetscCall(DMCopyDisc(dm, dm->dmBC));
    6601:     PetscCall(PetscSectionClone(section, &newSection));
    6602:     PetscCall(DMSetLocalSection(dm->dmBC, newSection));
    6603:     PetscCall(PetscSectionDestroy(&newSection));
    6604:     PetscCall(DMGetNaturalSF(dm, &sfNatural));
    6605:     PetscCall(DMSetNaturalSF(dm->dmBC, sfNatural));
    6606:     PetscCall(DMGetPointSF(dm->dmBC, &sf));
    6607:     PetscCall(PetscSectionCreateGlobalSection(section, sf, usePerm, PETSC_TRUE, PETSC_FALSE, &gsection));
    6608:     PetscCall(DMSetGlobalSection(dm->dmBC, gsection));
    6609:     PetscCall(PetscSectionDestroy(&gsection));
    6610:   }
    6611:   *odm = dm->dmBC;
    6612:   PetscFunctionReturn(PETSC_SUCCESS);
    6613: }

    6615: /*@
    6616:   DMGetOutputSequenceNumber - Retrieve the sequence number/value for output

    6618:   Input Parameter:
    6619: . dm - The original `DM`

    6621:   Output Parameters:
    6622: + num - The output sequence number
    6623: - val - The output sequence value

    6625:   Level: intermediate

    6627:   Note:
    6628:   This is intended for output that should appear in sequence, for instance
    6629:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6631:   Developer Note:
    6632:   The `DM` serves as a convenient place to store the current iteration value. The iteration is not
    6633:   not directly related to the `DM`.

    6635: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6636: @*/
    6637: PetscErrorCode DMGetOutputSequenceNumber(DM dm, PetscInt *num, PetscReal *val)
    6638: {
    6639:   PetscFunctionBegin;
    6641:   if (num) {
    6642:     PetscAssertPointer(num, 2);
    6643:     *num = dm->outputSequenceNum;
    6644:   }
    6645:   if (val) {
    6646:     PetscAssertPointer(val, 3);
    6647:     *val = dm->outputSequenceVal;
    6648:   }
    6649:   PetscFunctionReturn(PETSC_SUCCESS);
    6650: }

    6652: /*@
    6653:   DMSetOutputSequenceNumber - Set the sequence number/value for output

    6655:   Input Parameters:
    6656: + dm  - The original `DM`
    6657: . num - The output sequence number
    6658: - val - The output sequence value

    6660:   Level: intermediate

    6662:   Note:
    6663:   This is intended for output that should appear in sequence, for instance
    6664:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6666: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6667: @*/
    6668: PetscErrorCode DMSetOutputSequenceNumber(DM dm, PetscInt num, PetscReal val)
    6669: {
    6670:   PetscFunctionBegin;
    6672:   dm->outputSequenceNum = num;
    6673:   dm->outputSequenceVal = val;
    6674:   PetscFunctionReturn(PETSC_SUCCESS);
    6675: }

    6677: /*@
    6678:   DMOutputSequenceLoad - Retrieve the sequence value from a `PetscViewer`

    6680:   Input Parameters:
    6681: + dm     - The original `DM`
    6682: . viewer - The `PetscViewer` to get it from
    6683: . name   - The sequence name
    6684: - num    - The output sequence number

    6686:   Output Parameter:
    6687: . val - The output sequence value

    6689:   Level: intermediate

    6691:   Note:
    6692:   This is intended for output that should appear in sequence, for instance
    6693:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6695:   Developer Note:
    6696:   It is unclear at the user API level why a `DM` is needed as input

    6698: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6699: @*/
    6700: PetscErrorCode DMOutputSequenceLoad(DM dm, PetscViewer viewer, const char name[], PetscInt num, PetscReal *val)
    6701: {
    6702:   PetscBool ishdf5;

    6704:   PetscFunctionBegin;
    6707:   PetscAssertPointer(name, 3);
    6708:   PetscAssertPointer(val, 5);
    6709:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6710:   PetscCheck(ishdf5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6711: #if defined(PETSC_HAVE_HDF5)
    6712:   PetscScalar value;

    6714:   PetscCall(DMSequenceLoad_HDF5_Internal(dm, name, num, &value, viewer));
    6715:   *val = PetscRealPart(value);
    6716: #endif
    6717:   PetscFunctionReturn(PETSC_SUCCESS);
    6718: }

    6720: /*@
    6721:   DMGetOutputSequenceLength - Retrieve the number of sequence values from a `PetscViewer`

    6723:   Input Parameters:
    6724: + dm     - The original `DM`
    6725: . viewer - The `PetscViewer` to get it from
    6726: - name   - The sequence name

    6728:   Output Parameter:
    6729: . len - The length of the output sequence

    6731:   Level: intermediate

    6733:   Note:
    6734:   This is intended for output that should appear in sequence, for instance
    6735:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6737:   Developer Note:
    6738:   It is unclear at the user API level why a `DM` is needed as input

    6740: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6741: @*/
    6742: PetscErrorCode DMGetOutputSequenceLength(DM dm, PetscViewer viewer, const char name[], PetscInt *len)
    6743: {
    6744:   PetscBool ishdf5;

    6746:   PetscFunctionBegin;
    6749:   PetscAssertPointer(name, 3);
    6750:   PetscAssertPointer(len, 4);
    6751:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6752:   PetscCheck(ishdf5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6753: #if defined(PETSC_HAVE_HDF5)
    6754:   PetscCall(DMSequenceGetLength_HDF5_Internal(dm, name, len, viewer));
    6755: #endif
    6756:   PetscFunctionReturn(PETSC_SUCCESS);
    6757: }

    6759: /*@
    6760:   DMGetUseNatural - Get the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6762:   Not Collective

    6764:   Input Parameter:
    6765: . dm - The `DM`

    6767:   Output Parameter:
    6768: . useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6770:   Level: beginner

    6772: .seealso: [](ch_dmbase), `DM`, `DMSetUseNatural()`, `DMCreate()`
    6773: @*/
    6774: PetscErrorCode DMGetUseNatural(DM dm, PetscBool *useNatural)
    6775: {
    6776:   PetscFunctionBegin;
    6778:   PetscAssertPointer(useNatural, 2);
    6779:   *useNatural = dm->useNatural;
    6780:   PetscFunctionReturn(PETSC_SUCCESS);
    6781: }

    6783: /*@
    6784:   DMSetUseNatural - Set the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6786:   Collective

    6788:   Input Parameters:
    6789: + dm         - The `DM`
    6790: - useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6792:   Level: beginner

    6794:   Note:
    6795:   This also causes the map to be build after `DMCreateSubDM()` and `DMCreateSuperDM()`

    6797: .seealso: [](ch_dmbase), `DM`, `DMGetUseNatural()`, `DMCreate()`, `DMPlexDistribute()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    6798: @*/
    6799: PetscErrorCode DMSetUseNatural(DM dm, PetscBool useNatural)
    6800: {
    6801:   PetscFunctionBegin;
    6804:   dm->useNatural = useNatural;
    6805:   PetscFunctionReturn(PETSC_SUCCESS);
    6806: }

    6808: /*@
    6809:   DMCreateLabel - Create a label of the given name if it does not already exist in the `DM`

    6811:   Not Collective

    6813:   Input Parameters:
    6814: + dm   - The `DM` object
    6815: - name - The label name

    6817:   Level: intermediate

    6819: .seealso: [](ch_dmbase), `DM`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6820: @*/
    6821: PetscErrorCode DMCreateLabel(DM dm, const char name[])
    6822: {
    6823:   PetscBool flg;
    6824:   DMLabel   label;

    6826:   PetscFunctionBegin;
    6828:   PetscAssertPointer(name, 2);
    6829:   PetscCall(DMHasLabel(dm, name, &flg));
    6830:   if (!flg) {
    6831:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6832:     PetscCall(DMAddLabel(dm, label));
    6833:     PetscCall(DMLabelDestroy(&label));
    6834:   }
    6835:   PetscFunctionReturn(PETSC_SUCCESS);
    6836: }

    6838: /*@
    6839:   DMCreateLabelAtIndex - Create a label of the given name at the given index. If it already exists in the `DM`, move it to this index.

    6841:   Not Collective

    6843:   Input Parameters:
    6844: + dm   - The `DM` object
    6845: . l    - The index for the label
    6846: - name - The label name

    6848:   Level: intermediate

    6850: .seealso: [](ch_dmbase), `DM`, `DMCreateLabel()`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6851: @*/
    6852: PetscErrorCode DMCreateLabelAtIndex(DM dm, PetscInt l, const char name[])
    6853: {
    6854:   DMLabelLink orig, prev = NULL;
    6855:   DMLabel     label;
    6856:   PetscInt    Nl, m;
    6857:   PetscBool   flg, match;
    6858:   const char *lname;

    6860:   PetscFunctionBegin;
    6862:   PetscAssertPointer(name, 3);
    6863:   PetscCall(DMHasLabel(dm, name, &flg));
    6864:   if (!flg) {
    6865:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6866:     PetscCall(DMAddLabel(dm, label));
    6867:     PetscCall(DMLabelDestroy(&label));
    6868:   }
    6869:   PetscCall(DMGetNumLabels(dm, &Nl));
    6870:   PetscCheck(l < Nl, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label index %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", l, Nl);
    6871:   for (m = 0, orig = dm->labels; m < Nl; ++m, prev = orig, orig = orig->next) {
    6872:     PetscCall(PetscObjectGetName((PetscObject)orig->label, &lname));
    6873:     PetscCall(PetscStrcmp(name, lname, &match));
    6874:     if (match) break;
    6875:   }
    6876:   if (m == l) PetscFunctionReturn(PETSC_SUCCESS);
    6877:   if (!m) dm->labels = orig->next;
    6878:   else prev->next = orig->next;
    6879:   if (!l) {
    6880:     orig->next = dm->labels;
    6881:     dm->labels = orig;
    6882:   } else {
    6883:     for (m = 0, prev = dm->labels; m < l - 1; ++m, prev = prev->next);
    6884:     orig->next = prev->next;
    6885:     prev->next = orig;
    6886:   }
    6887:   PetscFunctionReturn(PETSC_SUCCESS);
    6888: }

    6890: /*@
    6891:   DMGetLabelValue - Get the value in a `DMLabel` for the given point, with -1 as the default

    6893:   Not Collective

    6895:   Input Parameters:
    6896: + dm    - The `DM` object
    6897: . name  - The label name
    6898: - point - The mesh point

    6900:   Output Parameter:
    6901: . value - The label value for this point, or -1 if the point is not in the label

    6903:   Level: beginner

    6905: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6906: @*/
    6907: PetscErrorCode DMGetLabelValue(DM dm, const char name[], PetscInt point, PetscInt *value)
    6908: {
    6909:   DMLabel label;

    6911:   PetscFunctionBegin;
    6913:   PetscAssertPointer(name, 2);
    6914:   PetscCall(DMGetLabel(dm, name, &label));
    6915:   PetscCheck(label, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "No label named %s was found", name);
    6916:   PetscCall(DMLabelGetValue(label, point, value));
    6917:   PetscFunctionReturn(PETSC_SUCCESS);
    6918: }

    6920: /*@
    6921:   DMSetLabelValue - Add a point to a `DMLabel` with given value

    6923:   Not Collective

    6925:   Input Parameters:
    6926: + dm    - The `DM` object
    6927: . name  - The label name
    6928: . point - The mesh point
    6929: - value - The label value for this point

    6931:   Output Parameter:

    6933:   Level: beginner

    6935: .seealso: [](ch_dmbase), `DM`, `DMLabelSetValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    6936: @*/
    6937: PetscErrorCode DMSetLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6938: {
    6939:   DMLabel label;

    6941:   PetscFunctionBegin;
    6943:   PetscAssertPointer(name, 2);
    6944:   PetscCall(DMGetLabel(dm, name, &label));
    6945:   if (!label) {
    6946:     PetscCall(DMCreateLabel(dm, name));
    6947:     PetscCall(DMGetLabel(dm, name, &label));
    6948:   }
    6949:   PetscCall(DMLabelSetValue(label, point, value));
    6950:   PetscFunctionReturn(PETSC_SUCCESS);
    6951: }

    6953: /*@
    6954:   DMClearLabelValue - Remove a point from a `DMLabel` with given value

    6956:   Not Collective

    6958:   Input Parameters:
    6959: + dm    - The `DM` object
    6960: . name  - The label name
    6961: . point - The mesh point
    6962: - value - The label value for this point

    6964:   Level: beginner

    6966: .seealso: [](ch_dmbase), `DM`, `DMLabelClearValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6967: @*/
    6968: PetscErrorCode DMClearLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6969: {
    6970:   DMLabel label;

    6972:   PetscFunctionBegin;
    6974:   PetscAssertPointer(name, 2);
    6975:   PetscCall(DMGetLabel(dm, name, &label));
    6976:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6977:   PetscCall(DMLabelClearValue(label, point, value));
    6978:   PetscFunctionReturn(PETSC_SUCCESS);
    6979: }

    6981: /*@
    6982:   DMGetLabelSize - Get the value of `DMLabelGetNumValues()` of a `DMLabel` in the `DM`

    6984:   Not Collective

    6986:   Input Parameters:
    6987: + dm   - The `DM` object
    6988: - name - The label name

    6990:   Output Parameter:
    6991: . size - The number of different integer ids, or 0 if the label does not exist

    6993:   Level: beginner

    6995:   Developer Note:
    6996:   This should be renamed to something like `DMGetLabelNumValues()` or removed.

    6998: .seealso: [](ch_dmbase), `DM`, `DMLabelGetNumValues()`, `DMSetLabelValue()`, `DMGetLabel()`
    6999: @*/
    7000: PetscErrorCode DMGetLabelSize(DM dm, const char name[], PetscInt *size)
    7001: {
    7002:   DMLabel label;

    7004:   PetscFunctionBegin;
    7006:   PetscAssertPointer(name, 2);
    7007:   PetscAssertPointer(size, 3);
    7008:   PetscCall(DMGetLabel(dm, name, &label));
    7009:   *size = 0;
    7010:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7011:   PetscCall(DMLabelGetNumValues(label, size));
    7012:   PetscFunctionReturn(PETSC_SUCCESS);
    7013: }

    7015: /*@
    7016:   DMGetLabelIdIS - Get the `DMLabelGetValueIS()` from a `DMLabel` in the `DM`

    7018:   Not Collective

    7020:   Input Parameters:
    7021: + dm   - The `DM` object
    7022: - name - The label name

    7024:   Output Parameter:
    7025: . ids - The integer ids, or `NULL` if the label does not exist

    7027:   Level: beginner

    7029: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValueIS()`, `DMGetLabelSize()`
    7030: @*/
    7031: PetscErrorCode DMGetLabelIdIS(DM dm, const char name[], IS *ids)
    7032: {
    7033:   DMLabel label;

    7035:   PetscFunctionBegin;
    7037:   PetscAssertPointer(name, 2);
    7038:   PetscAssertPointer(ids, 3);
    7039:   PetscCall(DMGetLabel(dm, name, &label));
    7040:   *ids = NULL;
    7041:   if (label) PetscCall(DMLabelGetValueIS(label, ids));
    7042:   else {
    7043:     /* returning an empty IS */
    7044:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 0, NULL, PETSC_USE_POINTER, ids));
    7045:   }
    7046:   PetscFunctionReturn(PETSC_SUCCESS);
    7047: }

    7049: /*@
    7050:   DMGetStratumSize - Get the number of points in a label stratum

    7052:   Not Collective

    7054:   Input Parameters:
    7055: + dm    - The `DM` object
    7056: . name  - The label name of the stratum
    7057: - value - The stratum value

    7059:   Output Parameter:
    7060: . size - The number of points, also called the stratum size

    7062:   Level: beginner

    7064: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumSize()`, `DMGetLabelSize()`, `DMGetLabelIds()`
    7065: @*/
    7066: PetscErrorCode DMGetStratumSize(DM dm, const char name[], PetscInt value, PetscInt *size)
    7067: {
    7068:   DMLabel label;

    7070:   PetscFunctionBegin;
    7072:   PetscAssertPointer(name, 2);
    7073:   PetscAssertPointer(size, 4);
    7074:   PetscCall(DMGetLabel(dm, name, &label));
    7075:   *size = 0;
    7076:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7077:   PetscCall(DMLabelGetStratumSize(label, value, size));
    7078:   PetscFunctionReturn(PETSC_SUCCESS);
    7079: }

    7081: /*@
    7082:   DMGetStratumIS - Get the points in a label stratum

    7084:   Not Collective

    7086:   Input Parameters:
    7087: + dm    - The `DM` object
    7088: . name  - The label name
    7089: - value - The stratum value

    7091:   Output Parameter:
    7092: . points - The stratum points, or `NULL` if the label does not exist or does not have that value

    7094:   Level: beginner

    7096: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumIS()`, `DMGetStratumSize()`
    7097: @*/
    7098: PetscErrorCode DMGetStratumIS(DM dm, const char name[], PetscInt value, IS *points)
    7099: {
    7100:   DMLabel label;

    7102:   PetscFunctionBegin;
    7104:   PetscAssertPointer(name, 2);
    7105:   PetscAssertPointer(points, 4);
    7106:   PetscCall(DMGetLabel(dm, name, &label));
    7107:   *points = NULL;
    7108:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7109:   PetscCall(DMLabelGetStratumIS(label, value, points));
    7110:   PetscFunctionReturn(PETSC_SUCCESS);
    7111: }

    7113: /*@
    7114:   DMSetStratumIS - Set the points in a label stratum

    7116:   Not Collective

    7118:   Input Parameters:
    7119: + dm     - The `DM` object
    7120: . name   - The label name
    7121: . value  - The stratum value
    7122: - points - The stratum points

    7124:   Level: beginner

    7126: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMClearLabelStratum()`, `DMLabelClearStratum()`, `DMLabelSetStratumIS()`, `DMGetStratumSize()`
    7127: @*/
    7128: PetscErrorCode DMSetStratumIS(DM dm, const char name[], PetscInt value, IS points)
    7129: {
    7130:   DMLabel label;

    7132:   PetscFunctionBegin;
    7134:   PetscAssertPointer(name, 2);
    7136:   PetscCall(DMGetLabel(dm, name, &label));
    7137:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7138:   PetscCall(DMLabelSetStratumIS(label, value, points));
    7139:   PetscFunctionReturn(PETSC_SUCCESS);
    7140: }

    7142: /*@
    7143:   DMClearLabelStratum - Remove all points from a stratum from a `DMLabel`

    7145:   Not Collective

    7147:   Input Parameters:
    7148: + dm    - The `DM` object
    7149: . name  - The label name
    7150: - value - The label value for this point

    7152:   Output Parameter:

    7154:   Level: beginner

    7156: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMLabelClearStratum()`, `DMSetLabelValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    7157: @*/
    7158: PetscErrorCode DMClearLabelStratum(DM dm, const char name[], PetscInt value)
    7159: {
    7160:   DMLabel label;

    7162:   PetscFunctionBegin;
    7164:   PetscAssertPointer(name, 2);
    7165:   PetscCall(DMGetLabel(dm, name, &label));
    7166:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7167:   PetscCall(DMLabelClearStratum(label, value));
    7168:   PetscFunctionReturn(PETSC_SUCCESS);
    7169: }

    7171: /*@
    7172:   DMGetNumLabels - Return the number of labels defined by on the `DM`

    7174:   Not Collective

    7176:   Input Parameter:
    7177: . dm - The `DM` object

    7179:   Output Parameter:
    7180: . numLabels - the number of Labels

    7182:   Level: intermediate

    7184: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabelName()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7185: @*/
    7186: PetscErrorCode DMGetNumLabels(DM dm, PetscInt *numLabels)
    7187: {
    7188:   DMLabelLink next = dm->labels;
    7189:   PetscInt    n    = 0;

    7191:   PetscFunctionBegin;
    7193:   PetscAssertPointer(numLabels, 2);
    7194:   while (next) {
    7195:     ++n;
    7196:     next = next->next;
    7197:   }
    7198:   *numLabels = n;
    7199:   PetscFunctionReturn(PETSC_SUCCESS);
    7200: }

    7202: /*@
    7203:   DMGetLabelName - Return the name of nth label

    7205:   Not Collective

    7207:   Input Parameters:
    7208: + dm - The `DM` object
    7209: - n  - the label number

    7211:   Output Parameter:
    7212: . name - the label name

    7214:   Level: intermediate

    7216:   Developer Note:
    7217:   Some of the functions that appropriate on labels using their number have the suffix ByNum, others do not.

    7219: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7220: @*/
    7221: PetscErrorCode DMGetLabelName(DM dm, PetscInt n, const char *name[])
    7222: {
    7223:   DMLabelLink next = dm->labels;
    7224:   PetscInt    l    = 0;

    7226:   PetscFunctionBegin;
    7228:   PetscAssertPointer(name, 3);
    7229:   while (next) {
    7230:     if (l == n) {
    7231:       PetscCall(PetscObjectGetName((PetscObject)next->label, name));
    7232:       PetscFunctionReturn(PETSC_SUCCESS);
    7233:     }
    7234:     ++l;
    7235:     next = next->next;
    7236:   }
    7237:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7238: }

    7240: /*@
    7241:   DMHasLabel - Determine whether the `DM` has a label of a given name

    7243:   Not Collective

    7245:   Input Parameters:
    7246: + dm   - The `DM` object
    7247: - name - The label name

    7249:   Output Parameter:
    7250: . hasLabel - `PETSC_TRUE` if the label is present

    7252:   Level: intermediate

    7254: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabel()`, `DMGetLabelByNum()`, `DMCreateLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7255: @*/
    7256: PetscErrorCode DMHasLabel(DM dm, const char name[], PetscBool *hasLabel)
    7257: {
    7258:   DMLabelLink next = dm->labels;
    7259:   const char *lname;

    7261:   PetscFunctionBegin;
    7263:   PetscAssertPointer(name, 2);
    7264:   PetscAssertPointer(hasLabel, 3);
    7265:   *hasLabel = PETSC_FALSE;
    7266:   while (next) {
    7267:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7268:     PetscCall(PetscStrcmp(name, lname, hasLabel));
    7269:     if (*hasLabel) break;
    7270:     next = next->next;
    7271:   }
    7272:   PetscFunctionReturn(PETSC_SUCCESS);
    7273: }

    7275: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7276: /*@
    7277:   DMGetLabel - Return the label of a given name, or `NULL`, from a `DM`

    7279:   Not Collective

    7281:   Input Parameters:
    7282: + dm   - The `DM` object
    7283: - name - The label name

    7285:   Output Parameter:
    7286: . label - The `DMLabel`, or `NULL` if the label is absent

    7288:   Default labels in a `DMPLEX`:
    7289: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7290: . "celltype"    - Holds the topological type of each cell
    7291: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7292: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7293: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7294: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7296:   Level: intermediate

    7298: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMHasLabel()`, `DMGetLabelByNum()`, `DMAddLabel()`, `DMCreateLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7299: @*/
    7300: PetscErrorCode DMGetLabel(DM dm, const char name[], DMLabel *label)
    7301: {
    7302:   DMLabelLink next = dm->labels;
    7303:   PetscBool   hasLabel;
    7304:   const char *lname;

    7306:   PetscFunctionBegin;
    7308:   PetscAssertPointer(name, 2);
    7309:   PetscAssertPointer(label, 3);
    7310:   *label = NULL;
    7311:   while (next) {
    7312:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7313:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7314:     if (hasLabel) {
    7315:       *label = next->label;
    7316:       break;
    7317:     }
    7318:     next = next->next;
    7319:   }
    7320:   PetscFunctionReturn(PETSC_SUCCESS);
    7321: }

    7323: /*@
    7324:   DMGetLabelByNum - Return the nth label on a `DM`

    7326:   Not Collective

    7328:   Input Parameters:
    7329: + dm - The `DM` object
    7330: - n  - the label number

    7332:   Output Parameter:
    7333: . label - the label

    7335:   Level: intermediate

    7337: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7338: @*/
    7339: PetscErrorCode DMGetLabelByNum(DM dm, PetscInt n, DMLabel *label)
    7340: {
    7341:   DMLabelLink next = dm->labels;
    7342:   PetscInt    l    = 0;

    7344:   PetscFunctionBegin;
    7346:   PetscAssertPointer(label, 3);
    7347:   while (next) {
    7348:     if (l == n) {
    7349:       *label = next->label;
    7350:       PetscFunctionReturn(PETSC_SUCCESS);
    7351:     }
    7352:     ++l;
    7353:     next = next->next;
    7354:   }
    7355:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7356: }

    7358: /*@
    7359:   DMAddLabel - Add the label to this `DM`

    7361:   Not Collective

    7363:   Input Parameters:
    7364: + dm    - The `DM` object
    7365: - label - The `DMLabel`

    7367:   Level: developer

    7369: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7370: @*/
    7371: PetscErrorCode DMAddLabel(DM dm, DMLabel label)
    7372: {
    7373:   DMLabelLink l, *p, tmpLabel;
    7374:   PetscBool   hasLabel;
    7375:   const char *lname;
    7376:   PetscBool   flg;

    7378:   PetscFunctionBegin;
    7380:   PetscCall(PetscObjectGetName((PetscObject)label, &lname));
    7381:   PetscCall(DMHasLabel(dm, lname, &hasLabel));
    7382:   PetscCheck(!hasLabel, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in this DM", lname);
    7383:   PetscCall(PetscCalloc1(1, &tmpLabel));
    7384:   tmpLabel->label  = label;
    7385:   tmpLabel->output = PETSC_TRUE;
    7386:   for (p = &dm->labels; (l = *p); p = &l->next) { }
    7387:   *p = tmpLabel;
    7388:   PetscCall(PetscObjectReference((PetscObject)label));
    7389:   PetscCall(PetscStrcmp(lname, "depth", &flg));
    7390:   if (flg) dm->depthLabel = label;
    7391:   PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7392:   if (flg) dm->celltypeLabel = label;
    7393:   PetscFunctionReturn(PETSC_SUCCESS);
    7394: }

    7396: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7397: /*@
    7398:   DMSetLabel - Replaces the label of a given name, or ignores it if the name is not present

    7400:   Not Collective

    7402:   Input Parameters:
    7403: + dm    - The `DM` object
    7404: - label - The `DMLabel`, having the same name, to substitute

    7406:   Default labels in a `DMPLEX`:
    7407: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7408: . "celltype"    - Holds the topological type of each cell
    7409: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7410: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7411: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7412: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7414:   Level: intermediate

    7416: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7417: @*/
    7418: PetscErrorCode DMSetLabel(DM dm, DMLabel label)
    7419: {
    7420:   DMLabelLink next = dm->labels;
    7421:   PetscBool   hasLabel, flg;
    7422:   const char *name, *lname;

    7424:   PetscFunctionBegin;
    7427:   PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7428:   while (next) {
    7429:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7430:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7431:     if (hasLabel) {
    7432:       PetscCall(PetscObjectReference((PetscObject)label));
    7433:       PetscCall(PetscStrcmp(lname, "depth", &flg));
    7434:       if (flg) dm->depthLabel = label;
    7435:       PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7436:       if (flg) dm->celltypeLabel = label;
    7437:       PetscCall(DMLabelDestroy(&next->label));
    7438:       next->label = label;
    7439:       break;
    7440:     }
    7441:     next = next->next;
    7442:   }
    7443:   PetscFunctionReturn(PETSC_SUCCESS);
    7444: }

    7446: /*@
    7447:   DMRemoveLabel - Remove the label given by name from this `DM`

    7449:   Not Collective

    7451:   Input Parameters:
    7452: + dm   - The `DM` object
    7453: - name - The label name

    7455:   Output Parameter:
    7456: . label - The `DMLabel`, or `NULL` if the label is absent. Pass in `NULL` to call `DMLabelDestroy()` on the label, otherwise the
    7457:           caller is responsible for calling `DMLabelDestroy()`.

    7459:   Level: developer

    7461: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabelBySelf()`
    7462: @*/
    7463: PetscErrorCode DMRemoveLabel(DM dm, const char name[], DMLabel *label)
    7464: {
    7465:   DMLabelLink link, *pnext;
    7466:   PetscBool   hasLabel;
    7467:   const char *lname;

    7469:   PetscFunctionBegin;
    7471:   PetscAssertPointer(name, 2);
    7472:   if (label) {
    7473:     PetscAssertPointer(label, 3);
    7474:     *label = NULL;
    7475:   }
    7476:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7477:     PetscCall(PetscObjectGetName((PetscObject)link->label, &lname));
    7478:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7479:     if (hasLabel) {
    7480:       *pnext = link->next; /* Remove from list */
    7481:       PetscCall(PetscStrcmp(name, "depth", &hasLabel));
    7482:       if (hasLabel) dm->depthLabel = NULL;
    7483:       PetscCall(PetscStrcmp(name, "celltype", &hasLabel));
    7484:       if (hasLabel) dm->celltypeLabel = NULL;
    7485:       if (label) *label = link->label;
    7486:       else PetscCall(DMLabelDestroy(&link->label));
    7487:       PetscCall(PetscFree(link));
    7488:       break;
    7489:     }
    7490:   }
    7491:   PetscFunctionReturn(PETSC_SUCCESS);
    7492: }

    7494: /*@
    7495:   DMRemoveLabelBySelf - Remove the label from this `DM`

    7497:   Not Collective

    7499:   Input Parameters:
    7500: + dm           - The `DM` object
    7501: . label        - The `DMLabel` to be removed from the `DM`
    7502: - failNotFound - Should it fail if the label is not found in the `DM`?

    7504:   Level: developer

    7506:   Note:
    7507:   Only exactly the same instance is removed if found, name match is ignored.
    7508:   If the `DM` has an exclusive reference to the label, the label gets destroyed and
    7509:   *label nullified.

    7511: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabel()`
    7512: @*/
    7513: PetscErrorCode DMRemoveLabelBySelf(DM dm, DMLabel *label, PetscBool failNotFound)
    7514: {
    7515:   DMLabelLink link, *pnext;
    7516:   PetscBool   hasLabel = PETSC_FALSE;

    7518:   PetscFunctionBegin;
    7520:   PetscAssertPointer(label, 2);
    7521:   if (!*label && !failNotFound) PetscFunctionReturn(PETSC_SUCCESS);
    7524:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7525:     if (*label == link->label) {
    7526:       hasLabel = PETSC_TRUE;
    7527:       *pnext   = link->next; /* Remove from list */
    7528:       if (*label == dm->depthLabel) dm->depthLabel = NULL;
    7529:       if (*label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    7530:       if (((PetscObject)link->label)->refct < 2) *label = NULL; /* nullify if exclusive reference */
    7531:       PetscCall(DMLabelDestroy(&link->label));
    7532:       PetscCall(PetscFree(link));
    7533:       break;
    7534:     }
    7535:   }
    7536:   PetscCheck(hasLabel || !failNotFound, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Given label not found in DM");
    7537:   PetscFunctionReturn(PETSC_SUCCESS);
    7538: }

    7540: /*@
    7541:   DMGetLabelOutput - Get the output flag for a given label

    7543:   Not Collective

    7545:   Input Parameters:
    7546: + dm   - The `DM` object
    7547: - name - The label name

    7549:   Output Parameter:
    7550: . output - The flag for output

    7552:   Level: developer

    7554: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMSetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7555: @*/
    7556: PetscErrorCode DMGetLabelOutput(DM dm, const char name[], PetscBool *output)
    7557: {
    7558:   DMLabelLink next = dm->labels;
    7559:   const char *lname;

    7561:   PetscFunctionBegin;
    7563:   PetscAssertPointer(name, 2);
    7564:   PetscAssertPointer(output, 3);
    7565:   while (next) {
    7566:     PetscBool flg;

    7568:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7569:     PetscCall(PetscStrcmp(name, lname, &flg));
    7570:     if (flg) {
    7571:       *output = next->output;
    7572:       PetscFunctionReturn(PETSC_SUCCESS);
    7573:     }
    7574:     next = next->next;
    7575:   }
    7576:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7577: }

    7579: /*@
    7580:   DMSetLabelOutput - Set if a given label should be saved to a `PetscViewer` in calls to `DMView()`

    7582:   Not Collective

    7584:   Input Parameters:
    7585: + dm     - The `DM` object
    7586: . name   - The label name
    7587: - output - `PETSC_TRUE` to save the label to the viewer

    7589:   Level: developer

    7591: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetOutputFlag()`, `DMGetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7592: @*/
    7593: PetscErrorCode DMSetLabelOutput(DM dm, const char name[], PetscBool output)
    7594: {
    7595:   DMLabelLink next = dm->labels;
    7596:   const char *lname;

    7598:   PetscFunctionBegin;
    7600:   PetscAssertPointer(name, 2);
    7601:   while (next) {
    7602:     PetscBool flg;

    7604:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7605:     PetscCall(PetscStrcmp(name, lname, &flg));
    7606:     if (flg) {
    7607:       next->output = output;
    7608:       PetscFunctionReturn(PETSC_SUCCESS);
    7609:     }
    7610:     next = next->next;
    7611:   }
    7612:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7613: }

    7615: /*@
    7616:   DMCopyLabels - Copy labels from one `DM` mesh to another `DM` with a superset of the points

    7618:   Collective

    7620:   Input Parameters:
    7621: + dmA   - The `DM` object with initial labels
    7622: . dmB   - The `DM` object to which labels are copied
    7623: . mode  - Copy labels by pointers (`PETSC_OWN_POINTER`) or duplicate them (`PETSC_COPY_VALUES`)
    7624: . all   - Copy all labels including "depth", "dim", and "celltype" (`PETSC_TRUE`) which are otherwise ignored (`PETSC_FALSE`)
    7625: - emode - How to behave when a `DMLabel` in the source and destination `DM`s with the same name is encountered (see `DMCopyLabelsMode`)

    7627:   Level: intermediate

    7629:   Note:
    7630:   This is typically used when interpolating or otherwise adding to a mesh, or testing.

    7632: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`
    7633: @*/
    7634: PetscErrorCode DMCopyLabels(DM dmA, DM dmB, PetscCopyMode mode, PetscBool all, DMCopyLabelsMode emode)
    7635: {
    7636:   DMLabel     label, labelNew, labelOld;
    7637:   const char *name;
    7638:   PetscBool   flg;
    7639:   DMLabelLink link;

    7641:   PetscFunctionBegin;
    7646:   PetscCheck(mode != PETSC_USE_POINTER, PetscObjectComm((PetscObject)dmA), PETSC_ERR_SUP, "PETSC_USE_POINTER not supported for objects");
    7647:   if (dmA == dmB) PetscFunctionReturn(PETSC_SUCCESS);
    7648:   for (link = dmA->labels; link; link = link->next) {
    7649:     label = link->label;
    7650:     PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7651:     if (!all) {
    7652:       PetscCall(PetscStrcmp(name, "depth", &flg));
    7653:       if (flg) continue;
    7654:       PetscCall(PetscStrcmp(name, "dim", &flg));
    7655:       if (flg) continue;
    7656:       PetscCall(PetscStrcmp(name, "celltype", &flg));
    7657:       if (flg) continue;
    7658:     }
    7659:     PetscCall(DMGetLabel(dmB, name, &labelOld));
    7660:     if (labelOld) {
    7661:       switch (emode) {
    7662:       case DM_COPY_LABELS_KEEP:
    7663:         continue;
    7664:       case DM_COPY_LABELS_REPLACE:
    7665:         PetscCall(DMRemoveLabelBySelf(dmB, &labelOld, PETSC_TRUE));
    7666:         break;
    7667:       case DM_COPY_LABELS_FAIL:
    7668:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in destination DM", name);
    7669:       default:
    7670:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Unhandled DMCopyLabelsMode %d", (int)emode);
    7671:       }
    7672:     }
    7673:     if (mode == PETSC_COPY_VALUES) PetscCall(DMLabelDuplicate(label, &labelNew));
    7674:     else labelNew = label;
    7675:     PetscCall(DMAddLabel(dmB, labelNew));
    7676:     if (mode == PETSC_COPY_VALUES) PetscCall(DMLabelDestroy(&labelNew));
    7677:   }
    7678:   PetscFunctionReturn(PETSC_SUCCESS);
    7679: }

    7681: /*@C
    7682:   DMCompareLabels - Compare labels between two `DM` objects

    7684:   Collective; No Fortran Support

    7686:   Input Parameters:
    7687: + dm0 - First `DM` object
    7688: - dm1 - Second `DM` object

    7690:   Output Parameters:
    7691: + equal   - (Optional) Flag whether labels of `dm0` and `dm1` are the same
    7692: - message - (Optional) Message describing the difference, or `NULL` if there is no difference

    7694:   Level: intermediate

    7696:   Notes:
    7697:   The output flag equal will be the same on all processes.

    7699:   If equal is passed as `NULL` and difference is found, an error is thrown on all processes.

    7701:   Make sure to pass equal is `NULL` on all processes or none of them.

    7703:   The output message is set independently on each rank.

    7705:   message must be freed with `PetscFree()`

    7707:   If message is passed as `NULL` and a difference is found, the difference description is printed to `stderr` in synchronized manner.

    7709:   Make sure to pass message as `NULL` on all processes or no processes.

    7711:   Labels are matched by name. If the number of labels and their names are equal,
    7712:   `DMLabelCompare()` is used to compare each pair of labels with the same name.

    7714:   Developer Note:
    7715:   Cannot automatically generate the Fortran stub because `message` must be freed with `PetscFree()`

    7717: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`, `DMLabelCompare()`
    7718: @*/
    7719: PetscErrorCode DMCompareLabels(DM dm0, DM dm1, PetscBool *equal, char *message[]) PeNS
    7720: {
    7721:   PetscInt    n, i;
    7722:   char        msg[PETSC_MAX_PATH_LEN] = "";
    7723:   PetscBool   eq;
    7724:   MPI_Comm    comm;
    7725:   PetscMPIInt rank;

    7727:   PetscFunctionBegin;
    7730:   PetscCheckSameComm(dm0, 1, dm1, 2);
    7731:   if (equal) PetscAssertPointer(equal, 3);
    7732:   if (message) PetscAssertPointer(message, 4);
    7733:   PetscCall(PetscObjectGetComm((PetscObject)dm0, &comm));
    7734:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    7735:   {
    7736:     PetscInt n1;

    7738:     PetscCall(DMGetNumLabels(dm0, &n));
    7739:     PetscCall(DMGetNumLabels(dm1, &n1));
    7740:     eq = (PetscBool)(n == n1);
    7741:     if (!eq) PetscCall(PetscSNPrintf(msg, sizeof(msg), "Number of labels in dm0 = %" PetscInt_FMT " != %" PetscInt_FMT " = Number of labels in dm1", n, n1));
    7742:     PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPI_C_BOOL, MPI_LAND, comm));
    7743:     if (!eq) goto finish;
    7744:   }
    7745:   for (i = 0; i < n; i++) {
    7746:     DMLabel     l0, l1;
    7747:     const char *name;
    7748:     char       *msgInner;

    7750:     /* Ignore label order */
    7751:     PetscCall(DMGetLabelByNum(dm0, i, &l0));
    7752:     PetscCall(PetscObjectGetName((PetscObject)l0, &name));
    7753:     PetscCall(DMGetLabel(dm1, name, &l1));
    7754:     if (!l1) {
    7755:       PetscCall(PetscSNPrintf(msg, sizeof(msg), "Label \"%s\" (#%" PetscInt_FMT " in dm0) not found in dm1", name, i));
    7756:       eq = PETSC_FALSE;
    7757:       break;
    7758:     }
    7759:     PetscCall(DMLabelCompare(comm, l0, l1, &eq, &msgInner));
    7760:     PetscCall(PetscStrncpy(msg, msgInner, sizeof(msg)));
    7761:     PetscCall(PetscFree(msgInner));
    7762:     if (!eq) break;
    7763:   }
    7764:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPI_C_BOOL, MPI_LAND, comm));
    7765: finish:
    7766:   /* If message output arg not set, print to stderr */
    7767:   if (message) {
    7768:     *message = NULL;
    7769:     if (msg[0]) PetscCall(PetscStrallocpy(msg, message));
    7770:   } else {
    7771:     if (msg[0]) PetscCall(PetscSynchronizedFPrintf(comm, PETSC_STDERR, "[%d] %s\n", rank, msg));
    7772:     PetscCall(PetscSynchronizedFlush(comm, PETSC_STDERR));
    7773:   }
    7774:   /* If same output arg not ser and labels are not equal, throw error */
    7775:   if (equal) *equal = eq;
    7776:   else PetscCheck(eq, comm, PETSC_ERR_ARG_INCOMP, "DMLabels are not the same in dm0 and dm1");
    7777:   PetscFunctionReturn(PETSC_SUCCESS);
    7778: }

    7780: PetscErrorCode DMSetLabelValue_Fast(DM dm, DMLabel *label, const char name[], PetscInt point, PetscInt value)
    7781: {
    7782:   PetscFunctionBegin;
    7783:   PetscAssertPointer(label, 2);
    7784:   if (!*label) {
    7785:     PetscCall(DMCreateLabel(dm, name));
    7786:     PetscCall(DMGetLabel(dm, name, label));
    7787:   }
    7788:   PetscCall(DMLabelSetValue(*label, point, value));
    7789:   PetscFunctionReturn(PETSC_SUCCESS);
    7790: }

    7792: /*
    7793:   Many mesh programs, such as Triangle and TetGen, allow only a single label for each mesh point. Therefore, we would
    7794:   like to encode all label IDs using a single, universal label. We can do this by assigning an integer to every
    7795:   (label, id) pair in the DM.

    7797:   However, a mesh point can have multiple labels, so we must separate all these values. We will assign a bit range to
    7798:   each label.
    7799: */
    7800: PetscErrorCode DMUniversalLabelCreate(DM dm, DMUniversalLabel *universal)
    7801: {
    7802:   DMUniversalLabel ul;
    7803:   PetscBool       *active;
    7804:   PetscInt         pStart, pEnd, p, Nl, l, m;

    7806:   PetscFunctionBegin;
    7807:   PetscCall(PetscMalloc1(1, &ul));
    7808:   PetscCall(DMLabelCreate(PETSC_COMM_SELF, "universal", &ul->label));
    7809:   PetscCall(DMGetNumLabels(dm, &Nl));
    7810:   PetscCall(PetscCalloc1(Nl, &active));
    7811:   ul->Nl = 0;
    7812:   for (l = 0; l < Nl; ++l) {
    7813:     PetscBool   isdepth, iscelltype;
    7814:     const char *name;

    7816:     PetscCall(DMGetLabelName(dm, l, &name));
    7817:     PetscCall(PetscStrncmp(name, "depth", 6, &isdepth));
    7818:     PetscCall(PetscStrncmp(name, "celltype", 9, &iscelltype));
    7819:     active[l] = !(isdepth || iscelltype) ? PETSC_TRUE : PETSC_FALSE;
    7820:     if (active[l]) ++ul->Nl;
    7821:   }
    7822:   PetscCall(PetscCalloc5(ul->Nl, &ul->names, ul->Nl, &ul->indices, ul->Nl + 1, &ul->offsets, ul->Nl + 1, &ul->bits, ul->Nl, &ul->masks));
    7823:   ul->Nv = 0;
    7824:   for (l = 0, m = 0; l < Nl; ++l) {
    7825:     DMLabel     label;
    7826:     PetscInt    nv;
    7827:     const char *name;

    7829:     if (!active[l]) continue;
    7830:     PetscCall(DMGetLabelName(dm, l, &name));
    7831:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7832:     PetscCall(DMLabelGetNumValues(label, &nv));
    7833:     PetscCall(PetscStrallocpy(name, &ul->names[m]));
    7834:     ul->indices[m] = l;
    7835:     ul->Nv += nv;
    7836:     ul->offsets[m + 1] = nv;
    7837:     ul->bits[m + 1]    = PetscCeilReal(PetscLog2Real(nv + 1));
    7838:     ++m;
    7839:   }
    7840:   for (l = 1; l <= ul->Nl; ++l) {
    7841:     ul->offsets[l] = ul->offsets[l - 1] + ul->offsets[l];
    7842:     ul->bits[l]    = ul->bits[l - 1] + ul->bits[l];
    7843:   }
    7844:   for (l = 0; l < ul->Nl; ++l) {
    7845:     PetscInt b;

    7847:     ul->masks[l] = 0;
    7848:     for (b = ul->bits[l]; b < ul->bits[l + 1]; ++b) ul->masks[l] |= 1 << b;
    7849:   }
    7850:   PetscCall(PetscMalloc1(ul->Nv, &ul->values));
    7851:   for (l = 0, m = 0; l < Nl; ++l) {
    7852:     DMLabel         label;
    7853:     IS              valueIS;
    7854:     const PetscInt *varr;
    7855:     PetscInt        nv, v;

    7857:     if (!active[l]) continue;
    7858:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7859:     PetscCall(DMLabelGetNumValues(label, &nv));
    7860:     PetscCall(DMLabelGetValueIS(label, &valueIS));
    7861:     PetscCall(ISGetIndices(valueIS, &varr));
    7862:     for (v = 0; v < nv; ++v) ul->values[ul->offsets[m] + v] = varr[v];
    7863:     PetscCall(ISRestoreIndices(valueIS, &varr));
    7864:     PetscCall(ISDestroy(&valueIS));
    7865:     PetscCall(PetscSortInt(nv, &ul->values[ul->offsets[m]]));
    7866:     ++m;
    7867:   }
    7868:   PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
    7869:   for (p = pStart; p < pEnd; ++p) {
    7870:     PetscInt  uval   = 0;
    7871:     PetscBool marked = PETSC_FALSE;

    7873:     for (l = 0, m = 0; l < Nl; ++l) {
    7874:       DMLabel  label;
    7875:       PetscInt val, defval, loc, nv;

    7877:       if (!active[l]) continue;
    7878:       PetscCall(DMGetLabelByNum(dm, l, &label));
    7879:       PetscCall(DMLabelGetValue(label, p, &val));
    7880:       PetscCall(DMLabelGetDefaultValue(label, &defval));
    7881:       if (val == defval) {
    7882:         ++m;
    7883:         continue;
    7884:       }
    7885:       nv     = ul->offsets[m + 1] - ul->offsets[m];
    7886:       marked = PETSC_TRUE;
    7887:       PetscCall(PetscFindInt(val, nv, &ul->values[ul->offsets[m]], &loc));
    7888:       PetscCheck(loc >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Label value %" PetscInt_FMT " not found in compression array", val);
    7889:       uval += (loc + 1) << ul->bits[m];
    7890:       ++m;
    7891:     }
    7892:     if (marked) PetscCall(DMLabelSetValue(ul->label, p, uval));
    7893:   }
    7894:   PetscCall(PetscFree(active));
    7895:   *universal = ul;
    7896:   PetscFunctionReturn(PETSC_SUCCESS);
    7897: }

    7899: PetscErrorCode DMUniversalLabelDestroy(DMUniversalLabel *universal)
    7900: {
    7901:   PetscInt l;

    7903:   PetscFunctionBegin;
    7904:   for (l = 0; l < (*universal)->Nl; ++l) PetscCall(PetscFree((*universal)->names[l]));
    7905:   PetscCall(DMLabelDestroy(&(*universal)->label));
    7906:   PetscCall(PetscFree5((*universal)->names, (*universal)->indices, (*universal)->offsets, (*universal)->bits, (*universal)->masks));
    7907:   PetscCall(PetscFree((*universal)->values));
    7908:   PetscCall(PetscFree(*universal));
    7909:   *universal = NULL;
    7910:   PetscFunctionReturn(PETSC_SUCCESS);
    7911: }

    7913: PetscErrorCode DMUniversalLabelGetLabel(DMUniversalLabel ul, DMLabel *ulabel)
    7914: {
    7915:   PetscFunctionBegin;
    7916:   PetscAssertPointer(ulabel, 2);
    7917:   *ulabel = ul->label;
    7918:   PetscFunctionReturn(PETSC_SUCCESS);
    7919: }

    7921: PetscErrorCode DMUniversalLabelCreateLabels(DMUniversalLabel ul, PetscBool preserveOrder, DM dm)
    7922: {
    7923:   PetscInt Nl = ul->Nl, l;

    7925:   PetscFunctionBegin;
    7927:   for (l = 0; l < Nl; ++l) {
    7928:     if (preserveOrder) PetscCall(DMCreateLabelAtIndex(dm, ul->indices[l], ul->names[l]));
    7929:     else PetscCall(DMCreateLabel(dm, ul->names[l]));
    7930:   }
    7931:   if (preserveOrder) {
    7932:     for (l = 0; l < ul->Nl; ++l) {
    7933:       const char *name;
    7934:       PetscBool   match;

    7936:       PetscCall(DMGetLabelName(dm, ul->indices[l], &name));
    7937:       PetscCall(PetscStrcmp(name, ul->names[l], &match));
    7938:       PetscCheck(match, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Label %" PetscInt_FMT " name %s does not match new name %s", l, name, ul->names[l]);
    7939:     }
    7940:   }
    7941:   PetscFunctionReturn(PETSC_SUCCESS);
    7942: }

    7944: PetscErrorCode DMUniversalLabelSetLabelValue(DMUniversalLabel ul, DM dm, PetscBool useIndex, PetscInt p, PetscInt value)
    7945: {
    7946:   PetscInt l;

    7948:   PetscFunctionBegin;
    7949:   for (l = 0; l < ul->Nl; ++l) {
    7950:     DMLabel  label;
    7951:     PetscInt lval = (value & ul->masks[l]) >> ul->bits[l];

    7953:     if (lval) {
    7954:       if (useIndex) PetscCall(DMGetLabelByNum(dm, ul->indices[l], &label));
    7955:       else PetscCall(DMGetLabel(dm, ul->names[l], &label));
    7956:       PetscCall(DMLabelSetValue(label, p, ul->values[ul->offsets[l] + lval - 1]));
    7957:     }
    7958:   }
    7959:   PetscFunctionReturn(PETSC_SUCCESS);
    7960: }

    7962: /*@
    7963:   DMGetCoarseDM - Get the coarse `DM`from which this `DM` was obtained by refinement

    7965:   Not Collective

    7967:   Input Parameter:
    7968: . dm - The `DM` object

    7970:   Output Parameter:
    7971: . cdm - The coarse `DM`

    7973:   Level: intermediate

    7975: .seealso: [](ch_dmbase), `DM`, `DMSetCoarseDM()`, `DMCoarsen()`
    7976: @*/
    7977: PetscErrorCode DMGetCoarseDM(DM dm, DM *cdm)
    7978: {
    7979:   PetscFunctionBegin;
    7981:   PetscAssertPointer(cdm, 2);
    7982:   *cdm = dm->coarseMesh;
    7983:   PetscFunctionReturn(PETSC_SUCCESS);
    7984: }

    7986: /*@
    7987:   DMSetCoarseDM - Set the coarse `DM` from which this `DM` was obtained by refinement

    7989:   Input Parameters:
    7990: + dm  - The `DM` object
    7991: - cdm - The coarse `DM`

    7993:   Level: intermediate

    7995:   Note:
    7996:   Normally this is set automatically by `DMRefine()`

    7998: .seealso: [](ch_dmbase), `DM`, `DMGetCoarseDM()`, `DMCoarsen()`, `DMSetRefine()`, `DMSetFineDM()`
    7999: @*/
    8000: PetscErrorCode DMSetCoarseDM(DM dm, DM cdm)
    8001: {
    8002:   PetscFunctionBegin;
    8005:   if (dm == cdm) cdm = NULL;
    8006:   PetscCall(PetscObjectReference((PetscObject)cdm));
    8007:   PetscCall(DMDestroy(&dm->coarseMesh));
    8008:   dm->coarseMesh = cdm;
    8009:   PetscFunctionReturn(PETSC_SUCCESS);
    8010: }

    8012: /*@
    8013:   DMGetFineDM - Get the fine mesh from which this `DM` was obtained by coarsening

    8015:   Input Parameter:
    8016: . dm - The `DM` object

    8018:   Output Parameter:
    8019: . fdm - The fine `DM`

    8021:   Level: intermediate

    8023: .seealso: [](ch_dmbase), `DM`, `DMSetFineDM()`, `DMCoarsen()`, `DMRefine()`
    8024: @*/
    8025: PetscErrorCode DMGetFineDM(DM dm, DM *fdm)
    8026: {
    8027:   PetscFunctionBegin;
    8029:   PetscAssertPointer(fdm, 2);
    8030:   *fdm = dm->fineMesh;
    8031:   PetscFunctionReturn(PETSC_SUCCESS);
    8032: }

    8034: /*@
    8035:   DMSetFineDM - Set the fine mesh from which this was obtained by coarsening

    8037:   Input Parameters:
    8038: + dm  - The `DM` object
    8039: - fdm - The fine `DM`

    8041:   Level: developer

    8043:   Note:
    8044:   Normally this is set automatically by `DMCoarsen()`

    8046: .seealso: [](ch_dmbase), `DM`, `DMGetFineDM()`, `DMCoarsen()`, `DMRefine()`
    8047: @*/
    8048: PetscErrorCode DMSetFineDM(DM dm, DM fdm)
    8049: {
    8050:   PetscFunctionBegin;
    8053:   if (dm == fdm) fdm = NULL;
    8054:   PetscCall(PetscObjectReference((PetscObject)fdm));
    8055:   PetscCall(DMDestroy(&dm->fineMesh));
    8056:   dm->fineMesh = fdm;
    8057:   PetscFunctionReturn(PETSC_SUCCESS);
    8058: }

    8060: /*@C
    8061:   DMAddBoundary - Add a boundary condition, for a single field, to a model represented by a `DM`

    8063:   Collective

    8065:   Input Parameters:
    8066: + dm       - The `DM`, with a `PetscDS` that matches the problem being constrained
    8067: . type     - The type of condition, e.g. `DM_BC_ESSENTIAL_ANALYTIC`, `DM_BC_ESSENTIAL_FIELD` (Dirichlet), or `DM_BC_NATURAL` (Neumann)
    8068: . name     - The BC name
    8069: . label    - The label defining constrained points
    8070: . Nv       - The number of `DMLabel` values for constrained points
    8071: . values   - An array of values for constrained points
    8072: . field    - The field to constrain
    8073: . Nc       - The number of constrained field components (0 will constrain all components)
    8074: . comps    - An array of constrained component numbers
    8075: . bcFunc   - A pointwise function giving boundary values
    8076: . bcFunc_t - A pointwise function giving the time derivative of the boundary values, or `NULL`
    8077: - ctx      - An optional user context for bcFunc

    8079:   Output Parameter:
    8080: . bd - (Optional) Boundary number

    8082:   Options Database Keys:
    8083: + -bc_NAME values     - Overrides the boundary ids for boundary named NAME
    8084: - -bc_NAME_comp comps - Overrides the boundary components for boundary named NAME

    8086:   Level: intermediate

    8088:   Notes:
    8089:   If the `DM` is of type `DMPLEX` and the field is of type `PetscFE`, then this function completes the label using `DMPlexLabelComplete()`.

    8091:   Both bcFunc and bcFunc_t will depend on the boundary condition type. If the type if `DM_BC_ESSENTIAL`, then the calling sequence is\:
    8092: .vb
    8093:  void bcFunc(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar bcval[])
    8094: .ve

    8096:   If the type is `DM_BC_ESSENTIAL_FIELD` or other _FIELD value, then the calling sequence is\:

    8098: .vb
    8099:   void bcFunc(PetscInt dim, PetscInt Nf, PetscInt NfAux,
    8100:               const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
    8101:               const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
    8102:               PetscReal time, const PetscReal x[], PetscScalar bcval[])
    8103: .ve
    8104: + dim - the spatial dimension
    8105: . Nf - the number of fields
    8106: . uOff - the offset into u[] and u_t[] for each field
    8107: . uOff_x - the offset into u_x[] for each field
    8108: . u - each field evaluated at the current point
    8109: . u_t - the time derivative of each field evaluated at the current point
    8110: . u_x - the gradient of each field evaluated at the current point
    8111: . aOff - the offset into a[] and a_t[] for each auxiliary field
    8112: . aOff_x - the offset into a_x[] for each auxiliary field
    8113: . a - each auxiliary field evaluated at the current point
    8114: . a_t - the time derivative of each auxiliary field evaluated at the current point
    8115: . a_x - the gradient of auxiliary each field evaluated at the current point
    8116: . t - current time
    8117: . x - coordinates of the current point
    8118: . numConstants - number of constant parameters
    8119: . constants - constant parameters
    8120: - bcval - output values at the current point

    8122: .seealso: [](ch_dmbase), `DM`, `DSGetBoundary()`, `PetscDSAddBoundary()`
    8123: @*/
    8124: PetscErrorCode DMAddBoundary(DM dm, DMBoundaryConditionType type, const char name[], DMLabel label, PetscInt Nv, const PetscInt values[], PetscInt field, PetscInt Nc, const PetscInt comps[], PetscVoidFn *bcFunc, PetscVoidFn *bcFunc_t, PetscCtx ctx, PetscInt *bd)
    8125: {
    8126:   PetscDS ds;

    8128:   PetscFunctionBegin;
    8135:   PetscCheck(!dm->localSection, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Cannot add boundary to DM after creating local section");
    8136:   PetscCall(DMGetDS(dm, &ds));
    8137:   /* Complete label */
    8138:   if (label) {
    8139:     PetscObject  obj;
    8140:     PetscClassId id;

    8142:     PetscCall(DMGetField(dm, field, NULL, &obj));
    8143:     PetscCall(PetscObjectGetClassId(obj, &id));
    8144:     if (id == PETSCFE_CLASSID) {
    8145:       DM plex;

    8147:       PetscCall(DMConvert(dm, DMPLEX, &plex));
    8148:       if (plex) PetscCall(DMPlexLabelComplete(plex, label));
    8149:       PetscCall(DMDestroy(&plex));
    8150:     }
    8151:   }
    8152:   PetscCall(PetscDSAddBoundary(ds, type, name, label, Nv, values, field, Nc, comps, bcFunc, bcFunc_t, ctx, bd));
    8153:   PetscFunctionReturn(PETSC_SUCCESS);
    8154: }

    8156: /* TODO Remove this since now the structures are the same */
    8157: static PetscErrorCode DMPopulateBoundary(DM dm)
    8158: {
    8159:   PetscDS     ds;
    8160:   DMBoundary *lastnext;
    8161:   DSBoundary  dsbound;

    8163:   PetscFunctionBegin;
    8164:   PetscCall(DMGetDS(dm, &ds));
    8165:   dsbound = ds->boundary;
    8166:   if (dm->boundary) {
    8167:     DMBoundary next = dm->boundary;

    8169:     /* quick check to see if the PetscDS has changed */
    8170:     if (next->dsboundary == dsbound) PetscFunctionReturn(PETSC_SUCCESS);
    8171:     /* the PetscDS has changed: tear down and rebuild */
    8172:     while (next) {
    8173:       DMBoundary b = next;

    8175:       next = b->next;
    8176:       PetscCall(PetscFree(b));
    8177:     }
    8178:     dm->boundary = NULL;
    8179:   }

    8181:   lastnext = &dm->boundary;
    8182:   while (dsbound) {
    8183:     DMBoundary dmbound;

    8185:     PetscCall(PetscNew(&dmbound));
    8186:     dmbound->dsboundary = dsbound;
    8187:     dmbound->label      = dsbound->label;
    8188:     /* push on the back instead of the front so that it is in the same order as in the PetscDS */
    8189:     *lastnext = dmbound;
    8190:     lastnext  = &dmbound->next;
    8191:     dsbound   = dsbound->next;
    8192:   }
    8193:   PetscFunctionReturn(PETSC_SUCCESS);
    8194: }

    8196: /* TODO: missing manual page */
    8197: PetscErrorCode DMIsBoundaryPoint(DM dm, PetscInt point, PetscBool *isBd)
    8198: {
    8199:   DMBoundary b;

    8201:   PetscFunctionBegin;
    8203:   PetscAssertPointer(isBd, 3);
    8204:   *isBd = PETSC_FALSE;
    8205:   PetscCall(DMPopulateBoundary(dm));
    8206:   b = dm->boundary;
    8207:   while (b && !*isBd) {
    8208:     DMLabel    label = b->label;
    8209:     DSBoundary dsb   = b->dsboundary;
    8210:     PetscInt   i;

    8212:     if (label) {
    8213:       for (i = 0; i < dsb->Nv && !*isBd; ++i) PetscCall(DMLabelStratumHasPoint(label, dsb->values[i], point, isBd));
    8214:     }
    8215:     b = b->next;
    8216:   }
    8217:   PetscFunctionReturn(PETSC_SUCCESS);
    8218: }

    8220: /*@
    8221:   DMHasBound - Determine whether a bound condition was specified

    8223:   Logically collective

    8225:   Input Parameter:
    8226: . dm - The `DM`, with a `PetscDS` that matches the problem being constrained

    8228:   Output Parameter:
    8229: . hasBound - Flag indicating if a bound condition was specified

    8231:   Level: intermediate

    8233: .seealso: [](ch_dmbase), `DM`, `DSAddBoundary()`, `PetscDSAddBoundary()`
    8234: @*/
    8235: PetscErrorCode DMHasBound(DM dm, PetscBool *hasBound)
    8236: {
    8237:   PetscDS  ds;
    8238:   PetscInt Nf, numBd;

    8240:   PetscFunctionBegin;
    8241:   *hasBound = PETSC_FALSE;
    8242:   PetscCall(DMGetDS(dm, &ds));
    8243:   PetscCall(PetscDSGetNumFields(ds, &Nf));
    8244:   for (PetscInt f = 0; f < Nf; ++f) {
    8245:     PetscSimplePointFn *lfunc, *ufunc;

    8247:     PetscCall(PetscDSGetLowerBound(ds, f, &lfunc, NULL));
    8248:     PetscCall(PetscDSGetUpperBound(ds, f, &ufunc, NULL));
    8249:     if (lfunc || ufunc) *hasBound = PETSC_TRUE;
    8250:   }

    8252:   PetscCall(PetscDSGetNumBoundary(ds, &numBd));
    8253:   PetscCall(PetscDSUpdateBoundaryLabels(ds, dm));
    8254:   for (PetscInt b = 0; b < numBd; ++b) {
    8255:     PetscWeakForm           wf;
    8256:     DMBoundaryConditionType type;
    8257:     const char             *name;
    8258:     DMLabel                 label;
    8259:     PetscInt                numids;
    8260:     const PetscInt         *ids;
    8261:     PetscInt                field, Nc;
    8262:     const PetscInt         *comps;
    8263:     PetscVoidFn            *bvfunc;
    8264:     void                   *ctx;

    8266:     PetscCall(PetscDSGetBoundary(ds, b, &wf, &type, &name, &label, &numids, &ids, &field, &Nc, &comps, &bvfunc, NULL, &ctx));
    8267:     if (type == DM_BC_LOWER_BOUND || type == DM_BC_UPPER_BOUND) *hasBound = PETSC_TRUE;
    8268:   }
    8269:   PetscFunctionReturn(PETSC_SUCCESS);
    8270: }

    8272: /*@C
    8273:   DMProjectFunction - This projects the given function into the function space provided by a `DM`, putting the coefficients in a global vector.

    8275:   Collective

    8277:   Input Parameters:
    8278: + dm    - The `DM`
    8279: . time  - The time
    8280: . funcs - The coordinate functions to evaluate, one per field
    8281: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8282: - mode  - The insertion mode for values

    8284:   Output Parameter:
    8285: . X - vector

    8287:   Calling sequence of `funcs`:
    8288: + dim  - The spatial dimension
    8289: . time - The time at which to sample
    8290: . x    - The coordinates
    8291: . Nc   - The number of components
    8292: . u    - The output field values
    8293: - ctx  - optional function context

    8295:   Level: developer

    8297:   Developer Notes:
    8298:   This API is specific to only particular usage of `DM`

    8300:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8302: .seealso: [](ch_dmbase), `DM`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8303: @*/
    8304: PetscErrorCode DMProjectFunction(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, PetscCtx ctx), void **ctxs, InsertMode mode, Vec X)
    8305: {
    8306:   Vec localX;

    8308:   PetscFunctionBegin;
    8310:   PetscCall(PetscLogEventBegin(DM_ProjectFunction, dm, X, 0, 0));
    8311:   PetscCall(DMGetLocalVector(dm, &localX));
    8312:   PetscCall(VecSet(localX, 0.));
    8313:   PetscCall(DMProjectFunctionLocal(dm, time, funcs, ctxs, mode, localX));
    8314:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8315:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8316:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8317:   PetscCall(PetscLogEventEnd(DM_ProjectFunction, dm, X, 0, 0));
    8318:   PetscFunctionReturn(PETSC_SUCCESS);
    8319: }

    8321: /*@C
    8322:   DMProjectFunctionLocal - This projects the given function into the function space provided by a `DM`, putting the coefficients in a local vector.

    8324:   Not Collective

    8326:   Input Parameters:
    8327: + dm    - The `DM`
    8328: . time  - The time
    8329: . funcs - The coordinate functions to evaluate, one per field
    8330: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8331: - mode  - The insertion mode for values

    8333:   Output Parameter:
    8334: . localX - vector

    8336:   Calling sequence of `funcs`:
    8337: + dim  - The spatial dimension
    8338: . time - The current timestep
    8339: . x    - The coordinates
    8340: . Nc   - The number of components
    8341: . u    - The output field values
    8342: - ctx  - optional function context

    8344:   Level: developer

    8346:   Developer Notes:
    8347:   This API is specific to only particular usage of `DM`

    8349:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8351: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8352: @*/
    8353: PetscErrorCode DMProjectFunctionLocal(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, PetscCtx ctx), void **ctxs, InsertMode mode, Vec localX)
    8354: {
    8355:   PetscFunctionBegin;
    8358:   PetscUseTypeMethod(dm, projectfunctionlocal, time, funcs, ctxs, mode, localX);
    8359:   PetscFunctionReturn(PETSC_SUCCESS);
    8360: }

    8362: /*@C
    8363:   DMProjectFunctionLabel - This projects the given function into the function space provided by the `DM`, putting the coefficients in a global vector, setting values only for points in the given label.

    8365:   Collective

    8367:   Input Parameters:
    8368: + dm     - The `DM`
    8369: . time   - The time
    8370: . numIds - The number of ids
    8371: . ids    - The ids
    8372: . Nc     - The number of components
    8373: . comps  - The components
    8374: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8375: . funcs  - The coordinate functions to evaluate, one per field
    8376: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs may be null.
    8377: - mode   - The insertion mode for values

    8379:   Output Parameter:
    8380: . X - vector

    8382:   Calling sequence of `funcs`:
    8383: + dim  - The spatial dimension
    8384: . time - The current timestep
    8385: . x    - The coordinates
    8386: . Nc   - The number of components
    8387: . u    - The output field values
    8388: - ctx  - optional function context

    8390:   Level: developer

    8392:   Developer Notes:
    8393:   This API is specific to only particular usage of `DM`

    8395:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8397: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabelLocal()`, `DMComputeL2Diff()`
    8398: @*/
    8399: PetscErrorCode DMProjectFunctionLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, PetscCtx ctx), void **ctxs, InsertMode mode, Vec X)
    8400: {
    8401:   Vec localX;

    8403:   PetscFunctionBegin;
    8405:   PetscCall(DMGetLocalVector(dm, &localX));
    8406:   PetscCall(VecSet(localX, 0.));
    8407:   PetscCall(DMProjectFunctionLabelLocal(dm, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX));
    8408:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8409:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8410:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8411:   PetscFunctionReturn(PETSC_SUCCESS);
    8412: }

    8414: /*@C
    8415:   DMProjectFunctionLabelLocal - This projects the given function into the function space provided by the `DM`, putting the coefficients in a local vector, setting values only for points in the given label.

    8417:   Not Collective

    8419:   Input Parameters:
    8420: + dm     - The `DM`
    8421: . time   - The time
    8422: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8423: . numIds - The number of ids
    8424: . ids    - The ids
    8425: . Nc     - The number of components
    8426: . comps  - The components
    8427: . funcs  - The coordinate functions to evaluate, one per field
    8428: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8429: - mode   - The insertion mode for values

    8431:   Output Parameter:
    8432: . localX - vector

    8434:   Calling sequence of `funcs`:
    8435: + dim  - The spatial dimension
    8436: . time - The current time
    8437: . x    - The coordinates
    8438: . Nc   - The number of components
    8439: . u    - The output field values
    8440: - ctx  - optional function context

    8442:   Level: developer

    8444:   Developer Notes:
    8445:   This API is specific to only particular usage of `DM`

    8447:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8449: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8450: @*/
    8451: PetscErrorCode DMProjectFunctionLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, PetscCtx ctx), void **ctxs, InsertMode mode, Vec localX)
    8452: {
    8453:   PetscFunctionBegin;
    8456:   PetscUseTypeMethod(dm, projectfunctionlabellocal, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX);
    8457:   PetscFunctionReturn(PETSC_SUCCESS);
    8458: }

    8460: /*@C
    8461:   DMProjectFieldLocal - This projects the given function of the input fields into the function space provided by the `DM`, putting the coefficients in a local vector.

    8463:   Not Collective

    8465:   Input Parameters:
    8466: + dm     - The `DM`
    8467: . time   - The time
    8468: . localU - The input field vector; may be `NULL` if projection is defined purely by coordinates
    8469: . funcs  - The functions to evaluate, one per field
    8470: - mode   - The insertion mode for values

    8472:   Output Parameter:
    8473: . localX - The output vector

    8475:   Calling sequence of `funcs`:
    8476: + dim          - The spatial dimension
    8477: . Nf           - The number of input fields
    8478: . NfAux        - The number of input auxiliary fields
    8479: . uOff         - The offset of each field in u[]
    8480: . uOff_x       - The offset of each field in u_x[]
    8481: . u            - The field values at this point in space
    8482: . u_t          - The field time derivative at this point in space (or `NULL`)
    8483: . u_x          - The field derivatives at this point in space
    8484: . aOff         - The offset of each auxiliary field in u[]
    8485: . aOff_x       - The offset of each auxiliary field in u_x[]
    8486: . a            - The auxiliary field values at this point in space
    8487: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8488: . a_x          - The auxiliary field derivatives at this point in space
    8489: . t            - The current time
    8490: . x            - The coordinates of this point
    8491: . numConstants - The number of constants
    8492: . constants    - The value of each constant
    8493: - f            - The value of the function at this point in space

    8495:   Level: intermediate

    8497:   Note:
    8498:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8499:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8500:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8501:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8503:   Developer Notes:
    8504:   This API is specific to only particular usage of `DM`

    8506:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8508: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`,
    8509: `DMProjectFunction()`, `DMComputeL2Diff()`
    8510: @*/
    8511: PetscErrorCode DMProjectFieldLocal(DM dm, PetscReal time, Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8512: {
    8513:   PetscFunctionBegin;
    8517:   PetscUseTypeMethod(dm, projectfieldlocal, time, localU, funcs, mode, localX);
    8518:   PetscFunctionReturn(PETSC_SUCCESS);
    8519: }

    8521: /*@C
    8522:   DMProjectFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain specified by the label.

    8524:   Not Collective

    8526:   Input Parameters:
    8527: + dm     - The `DM`
    8528: . time   - The time
    8529: . label  - The `DMLabel` marking the portion of the domain to output
    8530: . numIds - The number of label ids to use
    8531: . ids    - The label ids to use for marking
    8532: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8533: . comps  - The components to set in the output, or `NULL` for all components
    8534: . localU - The input field vector
    8535: . funcs  - The functions to evaluate, one per field
    8536: - mode   - The insertion mode for values

    8538:   Output Parameter:
    8539: . localX - The output vector

    8541:   Calling sequence of `funcs`:
    8542: + dim          - The spatial dimension
    8543: . Nf           - The number of input fields
    8544: . NfAux        - The number of input auxiliary fields
    8545: . uOff         - The offset of each field in u[]
    8546: . uOff_x       - The offset of each field in u_x[]
    8547: . u            - The field values at this point in space
    8548: . u_t          - The field time derivative at this point in space (or `NULL`)
    8549: . u_x          - The field derivatives at this point in space
    8550: . aOff         - The offset of each auxiliary field in u[]
    8551: . aOff_x       - The offset of each auxiliary field in u_x[]
    8552: . a            - The auxiliary field values at this point in space
    8553: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8554: . a_x          - The auxiliary field derivatives at this point in space
    8555: . t            - The current time
    8556: . x            - The coordinates of this point
    8557: . numConstants - The number of constants
    8558: . constants    - The value of each constant
    8559: - f            - The value of the function at this point in space

    8561:   Level: intermediate

    8563:   Note:
    8564:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8565:   The input `DM`, attached to localU, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8566:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8567:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8569:   Developer Notes:
    8570:   This API is specific to only particular usage of `DM`

    8572:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8574: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabel()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8575: @*/
    8576: PetscErrorCode DMProjectFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8577: {
    8578:   PetscFunctionBegin;
    8582:   PetscUseTypeMethod(dm, projectfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8583:   PetscFunctionReturn(PETSC_SUCCESS);
    8584: }

    8586: /*@C
    8587:   DMProjectFieldLabel - This projects the given function of the input fields into the function space provided, putting the coefficients in a global vector, calculating only over the portion of the domain specified by the label.

    8589:   Not Collective

    8591:   Input Parameters:
    8592: + dm     - The `DM`
    8593: . time   - The time
    8594: . label  - The `DMLabel` marking the portion of the domain to output
    8595: . numIds - The number of label ids to use
    8596: . ids    - The label ids to use for marking
    8597: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8598: . comps  - The components to set in the output, or `NULL` for all components
    8599: . U      - The input field vector
    8600: . funcs  - The functions to evaluate, one per field
    8601: - mode   - The insertion mode for values

    8603:   Output Parameter:
    8604: . X - The output vector

    8606:   Calling sequence of `funcs`:
    8607: + dim          - The spatial dimension
    8608: . Nf           - The number of input fields
    8609: . NfAux        - The number of input auxiliary fields
    8610: . uOff         - The offset of each field in u[]
    8611: . uOff_x       - The offset of each field in u_x[]
    8612: . u            - The field values at this point in space
    8613: . u_t          - The field time derivative at this point in space (or `NULL`)
    8614: . u_x          - The field derivatives at this point in space
    8615: . aOff         - The offset of each auxiliary field in u[]
    8616: . aOff_x       - The offset of each auxiliary field in u_x[]
    8617: . a            - The auxiliary field values at this point in space
    8618: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8619: . a_x          - The auxiliary field derivatives at this point in space
    8620: . t            - The current time
    8621: . x            - The coordinates of this point
    8622: . numConstants - The number of constants
    8623: . constants    - The value of each constant
    8624: - f            - The value of the function at this point in space

    8626:   Level: intermediate

    8628:   Note:
    8629:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8630:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8631:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8632:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8634:   Developer Notes:
    8635:   This API is specific to only particular usage of `DM`

    8637:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8639: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8640: @*/
    8641: PetscErrorCode DMProjectFieldLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec U, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec X)
    8642: {
    8643:   DM  dmIn;
    8644:   Vec localU, localX;

    8646:   PetscFunctionBegin;
    8648:   PetscCall(VecGetDM(U, &dmIn));
    8649:   PetscCall(DMGetLocalVector(dmIn, &localU));
    8650:   PetscCall(DMGetLocalVector(dm, &localX));
    8651:   PetscCall(VecSet(localX, 0.));
    8652:   PetscCall(DMGlobalToLocalBegin(dmIn, U, mode, localU));
    8653:   PetscCall(DMGlobalToLocalEnd(dmIn, U, mode, localU));
    8654:   PetscCall(DMProjectFieldLabelLocal(dm, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX));
    8655:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8656:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8657:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8658:   PetscCall(DMRestoreLocalVector(dmIn, &localU));
    8659:   PetscFunctionReturn(PETSC_SUCCESS);
    8660: }

    8662: /*@C
    8663:   DMProjectBdFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain boundary specified by the label.

    8665:   Not Collective

    8667:   Input Parameters:
    8668: + dm     - The `DM`
    8669: . time   - The time
    8670: . label  - The `DMLabel` marking the portion of the domain boundary to output
    8671: . numIds - The number of label ids to use
    8672: . ids    - The label ids to use for marking
    8673: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8674: . comps  - The components to set in the output, or `NULL` for all components
    8675: . localU - The input field vector
    8676: . funcs  - The functions to evaluate, one per field
    8677: - mode   - The insertion mode for values

    8679:   Output Parameter:
    8680: . localX - The output vector

    8682:   Calling sequence of `funcs`:
    8683: + dim          - The spatial dimension
    8684: . Nf           - The number of input fields
    8685: . NfAux        - The number of input auxiliary fields
    8686: . uOff         - The offset of each field in u[]
    8687: . uOff_x       - The offset of each field in u_x[]
    8688: . u            - The field values at this point in space
    8689: . u_t          - The field time derivative at this point in space (or `NULL`)
    8690: . u_x          - The field derivatives at this point in space
    8691: . aOff         - The offset of each auxiliary field in u[]
    8692: . aOff_x       - The offset of each auxiliary field in u_x[]
    8693: . a            - The auxiliary field values at this point in space
    8694: . a_t          - The auxiliary field time derivative at this point in space (or `NULL`)
    8695: . a_x          - The auxiliary field derivatives at this point in space
    8696: . t            - The current time
    8697: . x            - The coordinates of this point
    8698: . n            - The face normal
    8699: . numConstants - The number of constants
    8700: . constants    - The value of each constant
    8701: - f            - The value of the function at this point in space

    8703:   Level: intermediate

    8705:   Note:
    8706:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8707:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8708:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8709:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8711:   Developer Notes:
    8712:   This API is specific to only particular usage of `DM`

    8714:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8716: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8717: @*/
    8718: PetscErrorCode DMProjectBdFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], const PetscReal n[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8719: {
    8720:   PetscFunctionBegin;
    8724:   PetscUseTypeMethod(dm, projectbdfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8725:   PetscFunctionReturn(PETSC_SUCCESS);
    8726: }

    8728: /*@C
    8729:   DMComputeL2Diff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h.

    8731:   Collective

    8733:   Input Parameters:
    8734: + dm    - The `DM`
    8735: . time  - The time
    8736: . funcs - The functions to evaluate for each field component
    8737: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8738: - X     - The coefficient vector u_h, a global vector

    8740:   Output Parameter:
    8741: . diff - The diff ||u - u_h||_2

    8743:   Level: developer

    8745:   Developer Notes:
    8746:   This API is specific to only particular usage of `DM`

    8748:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8750: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2FieldDiff()`, `DMComputeL2GradientDiff()`
    8751: @*/
    8752: PetscErrorCode DMComputeL2Diff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal *diff)
    8753: {
    8754:   PetscFunctionBegin;
    8757:   PetscUseTypeMethod(dm, computel2diff, time, funcs, ctxs, X, diff);
    8758:   PetscFunctionReturn(PETSC_SUCCESS);
    8759: }

    8761: /*@C
    8762:   DMComputeL2GradientDiff - This function computes the L_2 difference between the gradient of a function u and an FEM interpolant solution grad u_h.

    8764:   Collective

    8766:   Input Parameters:
    8767: + dm    - The `DM`
    8768: . time  - The time
    8769: . funcs - The gradient functions to evaluate for each field component
    8770: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8771: . X     - The coefficient vector u_h, a global vector
    8772: - n     - The vector to project along

    8774:   Output Parameter:
    8775: . diff - The diff ||(grad u - grad u_h) . n||_2

    8777:   Level: developer

    8779:   Developer Notes:
    8780:   This API is specific to only particular usage of `DM`

    8782:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8784: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2Diff()`, `DMComputeL2FieldDiff()`
    8785: @*/
    8786: PetscErrorCode DMComputeL2GradientDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, const PetscReal n[], PetscReal *diff)
    8787: {
    8788:   PetscFunctionBegin;
    8791:   PetscUseTypeMethod(dm, computel2gradientdiff, time, funcs, ctxs, X, n, diff);
    8792:   PetscFunctionReturn(PETSC_SUCCESS);
    8793: }

    8795: /*@C
    8796:   DMComputeL2FieldDiff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h, separated into field components.

    8798:   Collective

    8800:   Input Parameters:
    8801: + dm    - The `DM`
    8802: . time  - The time
    8803: . funcs - The functions to evaluate for each field component
    8804: . ctxs  - Optional array of contexts to pass to each function, or `NULL`.
    8805: - X     - The coefficient vector u_h, a global vector

    8807:   Output Parameter:
    8808: . diff - The array of differences, ||u^f - u^f_h||_2

    8810:   Level: developer

    8812:   Developer Notes:
    8813:   This API is specific to only particular usage of `DM`

    8815:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8817: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2GradientDiff()`
    8818: @*/
    8819: PetscErrorCode DMComputeL2FieldDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal diff[])
    8820: {
    8821:   PetscFunctionBegin;
    8824:   PetscUseTypeMethod(dm, computel2fielddiff, time, funcs, ctxs, X, diff);
    8825:   PetscFunctionReturn(PETSC_SUCCESS);
    8826: }

    8828: /*@C
    8829:   DMGetNeighbors - Gets an array containing the MPI ranks of all the processes neighbors

    8831:   Not Collective

    8833:   Input Parameter:
    8834: . dm - The `DM`

    8836:   Output Parameters:
    8837: + nranks - the number of neighbours
    8838: - ranks  - the neighbors ranks

    8840:   Level: beginner

    8842:   Note:
    8843:   Do not free the array, it is freed when the `DM` is destroyed.

    8845: .seealso: [](ch_dmbase), `DM`, `DMDAGetNeighbors()`, `PetscSFGetRootRanks()`
    8846: @*/
    8847: PetscErrorCode DMGetNeighbors(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
    8848: {
    8849:   PetscFunctionBegin;
    8851:   PetscUseTypeMethod(dm, getneighbors, nranks, ranks);
    8852:   PetscFunctionReturn(PETSC_SUCCESS);
    8853: }

    8855: #include <petsc/private/matimpl.h>

    8857: /*
    8858:     Converts the input vector to a ghosted vector and then calls the standard coloring code.
    8859:     This must be a different function because it requires DM which is not defined in the Mat library
    8860: */
    8861: static PetscErrorCode MatFDColoringApply_AIJDM(Mat J, MatFDColoring coloring, Vec x1, void *sctx)
    8862: {
    8863:   PetscFunctionBegin;
    8864:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8865:     Vec x1local;
    8866:     DM  dm;
    8867:     PetscCall(MatGetDM(J, &dm));
    8868:     PetscCheck(dm, PetscObjectComm((PetscObject)J), PETSC_ERR_ARG_INCOMP, "IS_COLORING_LOCAL requires a DM");
    8869:     PetscCall(DMGetLocalVector(dm, &x1local));
    8870:     PetscCall(DMGlobalToLocalBegin(dm, x1, INSERT_VALUES, x1local));
    8871:     PetscCall(DMGlobalToLocalEnd(dm, x1, INSERT_VALUES, x1local));
    8872:     x1 = x1local;
    8873:   }
    8874:   PetscCall(MatFDColoringApply_AIJ(J, coloring, x1, sctx));
    8875:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8876:     DM dm;
    8877:     PetscCall(MatGetDM(J, &dm));
    8878:     PetscCall(DMRestoreLocalVector(dm, &x1));
    8879:   }
    8880:   PetscFunctionReturn(PETSC_SUCCESS);
    8881: }

    8883: /*@
    8884:   MatFDColoringUseDM - allows a `MatFDColoring` object to use the `DM` associated with the matrix to compute a `IS_COLORING_LOCAL` coloring

    8886:   Input Parameters:
    8887: + coloring   - The matrix to get the `DM` from
    8888: - fdcoloring - the `MatFDColoring` object

    8890:   Level: advanced

    8892:   Developer Note:
    8893:   This routine exists because the PETSc `Mat` library does not know about the `DM` objects

    8895: .seealso: [](ch_dmbase), `DM`, `MatFDColoring`, `MatFDColoringCreate()`, `ISColoringType`
    8896: @*/
    8897: PetscErrorCode MatFDColoringUseDM(Mat coloring, MatFDColoring fdcoloring)
    8898: {
    8899:   PetscFunctionBegin;
    8900:   coloring->ops->fdcoloringapply = MatFDColoringApply_AIJDM;
    8901:   PetscFunctionReturn(PETSC_SUCCESS);
    8902: }

    8904: /*@
    8905:   DMGetCompatibility - determine if two `DM`s are compatible

    8907:   Collective

    8909:   Input Parameters:
    8910: + dm1 - the first `DM`
    8911: - dm2 - the second `DM`

    8913:   Output Parameters:
    8914: + compatible - whether or not the two `DM`s are compatible
    8915: - set        - whether or not the compatible value was actually determined and set

    8917:   Level: advanced

    8919:   Notes:
    8920:   Two `DM`s are deemed compatible if they represent the same parallel decomposition
    8921:   of the same topology. This implies that the section (field data) on one
    8922:   "makes sense" with respect to the topology and parallel decomposition of the other.
    8923:   Loosely speaking, compatible `DM`s represent the same domain and parallel
    8924:   decomposition, but hold different data.

    8926:   Typically, one would confirm compatibility if intending to simultaneously iterate
    8927:   over a pair of vectors obtained from different `DM`s.

    8929:   For example, two `DMDA` objects are compatible if they have the same local
    8930:   and global sizes and the same stencil width. They can have different numbers
    8931:   of degrees of freedom per node. Thus, one could use the node numbering from
    8932:   either `DM` in bounds for a loop over vectors derived from either `DM`.

    8934:   Consider the operation of summing data living on a 2-dof `DMDA` to data living
    8935:   on a 1-dof `DMDA`, which should be compatible, as in the following snippet.
    8936: .vb
    8937:   ...
    8938:   PetscCall(DMGetCompatibility(da1,da2,&compatible,&set));
    8939:   if (set && compatible)  {
    8940:     PetscCall(DMDAVecGetArrayDOF(da1,vec1,&arr1));
    8941:     PetscCall(DMDAVecGetArrayDOF(da2,vec2,&arr2));
    8942:     PetscCall(DMDAGetCorners(da1,&x,&y,NULL,&m,&n,NULL));
    8943:     for (j=y; j<y+n; ++j) {
    8944:       for (i=x; i<x+m, ++i) {
    8945:         arr1[j][i][0] = arr2[j][i][0] + arr2[j][i][1];
    8946:       }
    8947:     }
    8948:     PetscCall(DMDAVecRestoreArrayDOF(da1,vec1,&arr1));
    8949:     PetscCall(DMDAVecRestoreArrayDOF(da2,vec2,&arr2));
    8950:   } else {
    8951:     SETERRQ(PetscObjectComm((PetscObject)da1,PETSC_ERR_ARG_INCOMP,"DMDA objects incompatible");
    8952:   }
    8953:   ...
    8954: .ve

    8956:   Checking compatibility might be expensive for a given implementation of `DM`,
    8957:   or might be impossible to unambiguously confirm or deny. For this reason,
    8958:   this function may decline to determine compatibility, and hence users should
    8959:   always check the "set" output parameter.

    8961:   A `DM` is always compatible with itself.

    8963:   In the current implementation, `DM`s which live on "unequal" communicators
    8964:   (MPI_UNEQUAL in the terminology of MPI_Comm_compare()) are always deemed
    8965:   incompatible.

    8967:   This function is labeled "Collective," as information about all subdomains
    8968:   is required on each rank. However, in `DM` implementations which store all this
    8969:   information locally, this function may be merely "Logically Collective".

    8971:   Developer Note:
    8972:   Compatibility is assumed to be a symmetric concept; `DM` A is compatible with `DM` B
    8973:   iff B is compatible with A. Thus, this function checks the implementations
    8974:   of both dm and dmc (if they are of different types), attempting to determine
    8975:   compatibility. It is left to `DM` implementers to ensure that symmetry is
    8976:   preserved. The simplest way to do this is, when implementing type-specific
    8977:   logic for this function, is to check for existing logic in the implementation
    8978:   of other `DM` types and let *set = PETSC_FALSE if found.

    8980: .seealso: [](ch_dmbase), `DM`, `DMDACreateCompatibleDMDA()`, `DMStagCreateCompatibleDMStag()`
    8981: @*/
    8982: PetscErrorCode DMGetCompatibility(DM dm1, DM dm2, PetscBool *compatible, PetscBool *set)
    8983: {
    8984:   PetscMPIInt compareResult;
    8985:   DMType      type, type2;
    8986:   PetscBool   sameType;

    8988:   PetscFunctionBegin;

    8992:   /* Declare a DM compatible with itself */
    8993:   if (dm1 == dm2) {
    8994:     *set        = PETSC_TRUE;
    8995:     *compatible = PETSC_TRUE;
    8996:     PetscFunctionReturn(PETSC_SUCCESS);
    8997:   }

    8999:   /* Declare a DM incompatible with a DM that lives on an "unequal"
    9000:      communicator. Note that this does not preclude compatibility with
    9001:      DMs living on "congruent" or "similar" communicators, but this must be
    9002:      determined by the implementation-specific logic */
    9003:   PetscCallMPI(MPI_Comm_compare(PetscObjectComm((PetscObject)dm1), PetscObjectComm((PetscObject)dm2), &compareResult));
    9004:   if (compareResult == MPI_UNEQUAL) {
    9005:     *set        = PETSC_TRUE;
    9006:     *compatible = PETSC_FALSE;
    9007:     PetscFunctionReturn(PETSC_SUCCESS);
    9008:   }

    9010:   /* Pass to the implementation-specific routine, if one exists. */
    9011:   if (dm1->ops->getcompatibility) {
    9012:     PetscUseTypeMethod(dm1, getcompatibility, dm2, compatible, set);
    9013:     if (*set) PetscFunctionReturn(PETSC_SUCCESS);
    9014:   }

    9016:   /* If dm1 and dm2 are of different types, then attempt to check compatibility
    9017:      with an implementation of this function from dm2 */
    9018:   PetscCall(DMGetType(dm1, &type));
    9019:   PetscCall(DMGetType(dm2, &type2));
    9020:   PetscCall(PetscStrcmp(type, type2, &sameType));
    9021:   if (!sameType && dm2->ops->getcompatibility) {
    9022:     PetscUseTypeMethod(dm2, getcompatibility, dm1, compatible, set); /* Note argument order */
    9023:   } else {
    9024:     *set = PETSC_FALSE;
    9025:   }
    9026:   PetscFunctionReturn(PETSC_SUCCESS);
    9027: }

    9029: /*@C
    9030:   DMMonitorSet - Sets an additional monitor function that is to be used after a solve to monitor discretization performance.

    9032:   Logically Collective

    9034:   Input Parameters:
    9035: + dm             - the `DM`
    9036: . f              - the monitor function
    9037: . mctx           - [optional] context for private data for the monitor routine (use `NULL` if no context is desired)
    9038: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence

    9040:   Options Database Key:
    9041: . -dm_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `DMMonitorSet()`, but
    9042:                        does not cancel those set via the options database.

    9044:   Level: intermediate

    9046:   Note:
    9047:   Several different monitoring routines may be set by calling
    9048:   `DMMonitorSet()` multiple times or with `DMMonitorSetFromOptions()`; all will be called in the
    9049:   order in which they were set.

    9051:   Fortran Note:
    9052:   Only a single monitor function can be set for each `DM` object

    9054:   Developer Note:
    9055:   This API has a generic name but seems specific to a very particular aspect of the use of `DM`

    9057: .seealso: [](ch_dmbase), `DM`, `DMMonitorCancel()`, `DMMonitorSetFromOptions()`, `DMMonitor()`, `PetscCtxDestroyFn`
    9058: @*/
    9059: PetscErrorCode DMMonitorSet(DM dm, PetscErrorCode (*f)(DM, void *), void *mctx, PetscCtxDestroyFn *monitordestroy)
    9060: {
    9061:   PetscFunctionBegin;
    9063:   for (PetscInt m = 0; m < dm->numbermonitors; ++m) {
    9064:     PetscBool identical;

    9066:     PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))(PetscVoidFn *)f, mctx, monitordestroy, (PetscErrorCode (*)(void))(PetscVoidFn *)dm->monitor[m], dm->monitorcontext[m], dm->monitordestroy[m], &identical));
    9067:     if (identical) PetscFunctionReturn(PETSC_SUCCESS);
    9068:   }
    9069:   PetscCheck(dm->numbermonitors < MAXDMMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
    9070:   dm->monitor[dm->numbermonitors]          = f;
    9071:   dm->monitordestroy[dm->numbermonitors]   = monitordestroy;
    9072:   dm->monitorcontext[dm->numbermonitors++] = mctx;
    9073:   PetscFunctionReturn(PETSC_SUCCESS);
    9074: }

    9076: /*@
    9077:   DMMonitorCancel - Clears all the monitor functions for a `DM` object.

    9079:   Logically Collective

    9081:   Input Parameter:
    9082: . dm - the DM

    9084:   Options Database Key:
    9085: . -dm_monitor_cancel - cancels all monitors that have been hardwired
    9086:   into a code by calls to `DMonitorSet()`, but does not cancel those
    9087:   set via the options database

    9089:   Level: intermediate

    9091:   Note:
    9092:   There is no way to clear one specific monitor from a `DM` object.

    9094: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`, `DMMonitor()`
    9095: @*/
    9096: PetscErrorCode DMMonitorCancel(DM dm)
    9097: {
    9098:   PetscInt m;

    9100:   PetscFunctionBegin;
    9102:   for (m = 0; m < dm->numbermonitors; ++m) {
    9103:     if (dm->monitordestroy[m]) PetscCall((*dm->monitordestroy[m])(&dm->monitorcontext[m]));
    9104:   }
    9105:   dm->numbermonitors = 0;
    9106:   PetscFunctionReturn(PETSC_SUCCESS);
    9107: }

    9109: /*@C
    9110:   DMMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user

    9112:   Collective

    9114:   Input Parameters:
    9115: + dm           - `DM` object you wish to monitor
    9116: . name         - the monitor type one is seeking
    9117: . help         - message indicating what monitoring is done
    9118: . manual       - manual page for the monitor
    9119: . monitor      - the monitor function, this must use a `PetscViewerFormat` as its context
    9120: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `DM` or `PetscViewer` objects

    9122:   Output Parameter:
    9123: . flg - Flag set if the monitor was created

    9125:   Calling sequence of `monitor`:
    9126: + dm  - the `DM` to be monitored
    9127: - ctx - monitor context

    9129:   Calling sequence of `monitorsetup`:
    9130: + dm - the `DM` to be monitored
    9131: - vf - the `PetscViewer` and format to be used by the monitor

    9133:   Level: developer

    9135: .seealso: [](ch_dmbase), `DM`, `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
    9136:           `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`,
    9137:           `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
    9138:           `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
    9139:           `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
    9140:           `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
    9141:           `PetscOptionsFList()`, `PetscOptionsEList()`, `DMMonitor()`, `DMMonitorSet()`
    9142: @*/
    9143: PetscErrorCode DMMonitorSetFromOptions(DM dm, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(DM dm, PetscCtx ctx), PetscErrorCode (*monitorsetup)(DM dm, PetscViewerAndFormat *vf), PetscBool *flg)
    9144: {
    9145:   PetscViewer       viewer;
    9146:   PetscViewerFormat format;

    9148:   PetscFunctionBegin;
    9150:   PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)dm), ((PetscObject)dm)->options, ((PetscObject)dm)->prefix, name, &viewer, &format, flg));
    9151:   if (*flg) {
    9152:     PetscViewerAndFormat *vf;

    9154:     PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
    9155:     PetscCall(PetscViewerDestroy(&viewer));
    9156:     if (monitorsetup) PetscCall((*monitorsetup)(dm, vf));
    9157:     PetscCall(DMMonitorSet(dm, monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
    9158:   }
    9159:   PetscFunctionReturn(PETSC_SUCCESS);
    9160: }

    9162: /*@
    9163:   DMMonitor - runs the user provided monitor routines, if they exist

    9165:   Collective

    9167:   Input Parameter:
    9168: . dm - The `DM`

    9170:   Level: developer

    9172:   Developer Note:
    9173:   Note should indicate when during the life of the `DM` the monitor is run. It appears to be
    9174:   related to the discretization process seems rather specialized since some `DM` have no
    9175:   concept of discretization.

    9177: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`
    9178: @*/
    9179: PetscErrorCode DMMonitor(DM dm)
    9180: {
    9181:   PetscInt m;

    9183:   PetscFunctionBegin;
    9184:   if (!dm) PetscFunctionReturn(PETSC_SUCCESS);
    9186:   for (m = 0; m < dm->numbermonitors; ++m) PetscCall((*dm->monitor[m])(dm, dm->monitorcontext[m]));
    9187:   PetscFunctionReturn(PETSC_SUCCESS);
    9188: }

    9190: /*@
    9191:   DMComputeError - Computes the error assuming the user has provided the exact solution functions

    9193:   Collective

    9195:   Input Parameters:
    9196: + dm  - The `DM`
    9197: - sol - The solution vector

    9199:   Input/Output Parameter:
    9200: . errors - An array of length Nf, the number of fields, or `NULL` for no output; on output
    9201:            contains the error in each field

    9203:   Output Parameter:
    9204: . errorVec - A vector to hold the cellwise error (may be `NULL`)

    9206:   Level: developer

    9208:   Note:
    9209:   The exact solutions come from the `PetscDS` object, and the time comes from `DMGetOutputSequenceNumber()`.

    9211: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMGetRegionNumDS()`, `PetscDSGetExactSolution()`, `DMGetOutputSequenceNumber()`
    9212: @*/
    9213: PetscErrorCode DMComputeError(DM dm, Vec sol, PetscReal errors[], Vec *errorVec)
    9214: {
    9215:   PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
    9216:   void    **ctxs;
    9217:   PetscReal time;
    9218:   PetscInt  Nf, f, Nds, s;

    9220:   PetscFunctionBegin;
    9221:   PetscCall(DMGetNumFields(dm, &Nf));
    9222:   PetscCall(PetscCalloc2(Nf, &exactSol, Nf, &ctxs));
    9223:   PetscCall(DMGetNumDS(dm, &Nds));
    9224:   for (s = 0; s < Nds; ++s) {
    9225:     PetscDS         ds;
    9226:     DMLabel         label;
    9227:     IS              fieldIS;
    9228:     const PetscInt *fields;
    9229:     PetscInt        dsNf;

    9231:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    9232:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    9233:     if (fieldIS) PetscCall(ISGetIndices(fieldIS, &fields));
    9234:     for (f = 0; f < dsNf; ++f) {
    9235:       const PetscInt field = fields[f];
    9236:       PetscCall(PetscDSGetExactSolution(ds, field, &exactSol[field], &ctxs[field]));
    9237:     }
    9238:     if (fieldIS) PetscCall(ISRestoreIndices(fieldIS, &fields));
    9239:   }
    9240:   for (f = 0; f < Nf; ++f) PetscCheck(exactSol[f], PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DS must contain exact solution functions in order to calculate error, missing for field %" PetscInt_FMT, f);
    9241:   PetscCall(DMGetOutputSequenceNumber(dm, NULL, &time));
    9242:   if (errors) PetscCall(DMComputeL2FieldDiff(dm, time, exactSol, ctxs, sol, errors));
    9243:   if (errorVec) {
    9244:     DM             edm;
    9245:     DMPolytopeType ct;
    9246:     PetscBool      simplex;
    9247:     PetscInt       dim, cStart, Nf;

    9249:     PetscCall(DMClone(dm, &edm));
    9250:     PetscCall(DMGetDimension(edm, &dim));
    9251:     PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    9252:     PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    9253:     simplex = DMPolytopeTypeGetNumVertices(ct) == DMPolytopeTypeGetDim(ct) + 1 ? PETSC_TRUE : PETSC_FALSE;
    9254:     PetscCall(DMGetNumFields(dm, &Nf));
    9255:     for (f = 0; f < Nf; ++f) {
    9256:       PetscFE         fe, efe;
    9257:       PetscQuadrature q;
    9258:       const char     *name;

    9260:       PetscCall(DMGetField(dm, f, NULL, (PetscObject *)&fe));
    9261:       PetscCall(PetscFECreateLagrange(PETSC_COMM_SELF, dim, Nf, simplex, 0, PETSC_DETERMINE, &efe));
    9262:       PetscCall(PetscObjectGetName((PetscObject)fe, &name));
    9263:       PetscCall(PetscObjectSetName((PetscObject)efe, name));
    9264:       PetscCall(PetscFEGetQuadrature(fe, &q));
    9265:       PetscCall(PetscFESetQuadrature(efe, q));
    9266:       PetscCall(DMSetField(edm, f, NULL, (PetscObject)efe));
    9267:       PetscCall(PetscFEDestroy(&efe));
    9268:     }
    9269:     PetscCall(DMCreateDS(edm));

    9271:     PetscCall(DMCreateGlobalVector(edm, errorVec));
    9272:     PetscCall(PetscObjectSetName((PetscObject)*errorVec, "Error"));
    9273:     PetscCall(DMPlexComputeL2DiffVec(dm, time, exactSol, ctxs, sol, *errorVec));
    9274:     PetscCall(DMDestroy(&edm));
    9275:   }
    9276:   PetscCall(PetscFree2(exactSol, ctxs));
    9277:   PetscFunctionReturn(PETSC_SUCCESS);
    9278: }

    9280: /*@
    9281:   DMGetNumAuxiliaryVec - Get the number of auxiliary vectors associated with this `DM`

    9283:   Not Collective

    9285:   Input Parameter:
    9286: . dm - The `DM`

    9288:   Output Parameter:
    9289: . numAux - The number of auxiliary data vectors

    9291:   Level: advanced

    9293: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMGetAuxiliaryVec()`
    9294: @*/
    9295: PetscErrorCode DMGetNumAuxiliaryVec(DM dm, PetscInt *numAux)
    9296: {
    9297:   PetscFunctionBegin;
    9299:   PetscCall(PetscHMapAuxGetSize(dm->auxData, numAux));
    9300:   PetscFunctionReturn(PETSC_SUCCESS);
    9301: }

    9303: /*@
    9304:   DMGetAuxiliaryVec - Get the auxiliary vector for region specified by the given label and value, and equation part

    9306:   Not Collective

    9308:   Input Parameters:
    9309: + dm    - The `DM`
    9310: . label - The `DMLabel`
    9311: . value - The label value indicating the region
    9312: - part  - The equation part, or 0 if unused

    9314:   Output Parameter:
    9315: . aux - The `Vec` holding auxiliary field data

    9317:   Level: advanced

    9319:   Note:
    9320:   If no auxiliary vector is found for this (label, value), (`NULL`, 0, 0) is checked as well.

    9322: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryLabels()`
    9323: @*/
    9324: PetscErrorCode DMGetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec *aux)
    9325: {
    9326:   PetscHashAuxKey key, wild = {NULL, 0, 0};
    9327:   PetscBool       has;

    9329:   PetscFunctionBegin;
    9332:   key.label = label;
    9333:   key.value = value;
    9334:   key.part  = part;
    9335:   PetscCall(PetscHMapAuxHas(dm->auxData, key, &has));
    9336:   if (has) PetscCall(PetscHMapAuxGet(dm->auxData, key, aux));
    9337:   else PetscCall(PetscHMapAuxGet(dm->auxData, wild, aux));
    9338:   PetscFunctionReturn(PETSC_SUCCESS);
    9339: }

    9341: /*@
    9342:   DMSetAuxiliaryVec - Set an auxiliary vector for region specified by the given label and value, and equation part

    9344:   Not Collective because auxiliary vectors are not parallel

    9346:   Input Parameters:
    9347: + dm    - The `DM`
    9348: . label - The `DMLabel`
    9349: . value - The label value indicating the region
    9350: . part  - The equation part, or 0 if unused
    9351: - aux   - The `Vec` holding auxiliary field data

    9353:   Level: advanced

    9355: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMCopyAuxiliaryVec()`
    9356: @*/
    9357: PetscErrorCode DMSetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec aux)
    9358: {
    9359:   Vec             old;
    9360:   PetscHashAuxKey key;

    9362:   PetscFunctionBegin;
    9365:   key.label = label;
    9366:   key.value = value;
    9367:   key.part  = part;
    9368:   PetscCall(PetscHMapAuxGet(dm->auxData, key, &old));
    9369:   PetscCall(PetscObjectReference((PetscObject)aux));
    9370:   if (!aux) PetscCall(PetscHMapAuxDel(dm->auxData, key));
    9371:   else PetscCall(PetscHMapAuxSet(dm->auxData, key, aux));
    9372:   PetscCall(VecDestroy(&old));
    9373:   PetscFunctionReturn(PETSC_SUCCESS);
    9374: }

    9376: /*@
    9377:   DMGetAuxiliaryLabels - Get the labels, values, and parts for all auxiliary vectors in this `DM`

    9379:   Not Collective

    9381:   Input Parameter:
    9382: . dm - The `DM`

    9384:   Output Parameters:
    9385: + labels - The `DMLabel`s for each `Vec`
    9386: . values - The label values for each `Vec`
    9387: - parts  - The equation parts for each `Vec`

    9389:   Level: advanced

    9391:   Note:
    9392:   The arrays passed in must be at least as large as `DMGetNumAuxiliaryVec()`.

    9394: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMCopyAuxiliaryVec()`
    9395: @*/
    9396: PetscErrorCode DMGetAuxiliaryLabels(DM dm, DMLabel labels[], PetscInt values[], PetscInt parts[])
    9397: {
    9398:   PetscHashAuxKey *keys;
    9399:   PetscInt         n, i, off = 0;

    9401:   PetscFunctionBegin;
    9403:   PetscAssertPointer(labels, 2);
    9404:   PetscAssertPointer(values, 3);
    9405:   PetscAssertPointer(parts, 4);
    9406:   PetscCall(DMGetNumAuxiliaryVec(dm, &n));
    9407:   PetscCall(PetscMalloc1(n, &keys));
    9408:   PetscCall(PetscHMapAuxGetKeys(dm->auxData, &off, keys));
    9409:   for (i = 0; i < n; ++i) {
    9410:     labels[i] = keys[i].label;
    9411:     values[i] = keys[i].value;
    9412:     parts[i]  = keys[i].part;
    9413:   }
    9414:   PetscCall(PetscFree(keys));
    9415:   PetscFunctionReturn(PETSC_SUCCESS);
    9416: }

    9418: /*@
    9419:   DMCopyAuxiliaryVec - Copy the auxiliary vector data on a `DM` to a new `DM`

    9421:   Not Collective

    9423:   Input Parameter:
    9424: . dm - The `DM`

    9426:   Output Parameter:
    9427: . dmNew - The new `DM`, now with the same auxiliary data

    9429:   Level: advanced

    9431:   Note:
    9432:   This is a shallow copy of the auxiliary vectors

    9434: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9435: @*/
    9436: PetscErrorCode DMCopyAuxiliaryVec(DM dm, DM dmNew)
    9437: {
    9438:   PetscFunctionBegin;
    9441:   if (dm == dmNew) PetscFunctionReturn(PETSC_SUCCESS);
    9442:   PetscCall(DMClearAuxiliaryVec(dmNew));

    9444:   PetscCall(PetscHMapAuxDestroy(&dmNew->auxData));
    9445:   PetscCall(PetscHMapAuxDuplicate(dm->auxData, &dmNew->auxData));
    9446:   {
    9447:     Vec     *auxData;
    9448:     PetscInt n, i, off = 0;

    9450:     PetscCall(PetscHMapAuxGetSize(dmNew->auxData, &n));
    9451:     PetscCall(PetscMalloc1(n, &auxData));
    9452:     PetscCall(PetscHMapAuxGetVals(dmNew->auxData, &off, auxData));
    9453:     for (i = 0; i < n; ++i) PetscCall(PetscObjectReference((PetscObject)auxData[i]));
    9454:     PetscCall(PetscFree(auxData));
    9455:   }
    9456:   PetscFunctionReturn(PETSC_SUCCESS);
    9457: }

    9459: /*@
    9460:   DMClearAuxiliaryVec - Destroys the auxiliary vector information and creates a new empty one

    9462:   Not Collective

    9464:   Input Parameter:
    9465: . dm - The `DM`

    9467:   Level: advanced

    9469: .seealso: [](ch_dmbase), `DM`, `DMCopyAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9470: @*/
    9471: PetscErrorCode DMClearAuxiliaryVec(DM dm)
    9472: {
    9473:   Vec     *auxData;
    9474:   PetscInt n, i, off = 0;

    9476:   PetscFunctionBegin;
    9477:   PetscCall(PetscHMapAuxGetSize(dm->auxData, &n));
    9478:   PetscCall(PetscMalloc1(n, &auxData));
    9479:   PetscCall(PetscHMapAuxGetVals(dm->auxData, &off, auxData));
    9480:   for (i = 0; i < n; ++i) PetscCall(VecDestroy(&auxData[i]));
    9481:   PetscCall(PetscFree(auxData));
    9482:   PetscCall(PetscHMapAuxDestroy(&dm->auxData));
    9483:   PetscCall(PetscHMapAuxCreate(&dm->auxData));
    9484:   PetscFunctionReturn(PETSC_SUCCESS);
    9485: }

    9487: /*@
    9488:   DMPolytopeMatchOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9490:   Not Collective

    9492:   Input Parameters:
    9493: + ct         - The `DMPolytopeType`
    9494: . sourceCone - The source arrangement of faces
    9495: - targetCone - The target arrangement of faces

    9497:   Output Parameters:
    9498: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9499: - found - Flag indicating that a suitable orientation was found

    9501:   Level: advanced

    9503:   Note:
    9504:   An arrangement is a face order combined with an orientation for each face

    9506:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9507:   that labels each arrangement (face ordering plus orientation for each face).

    9509:   See `DMPolytopeMatchVertexOrientation()` to find a new vertex orientation that takes the source vertex arrangement to the target vertex arrangement

    9511: .seealso: [](ch_dmbase), `DM`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetVertexOrientation()`
    9512: @*/
    9513: PetscErrorCode DMPolytopeMatchOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt, PetscBool *found)
    9514: {
    9515:   const PetscInt cS = DMPolytopeTypeGetConeSize(ct);
    9516:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9517:   PetscInt       o, c;

    9519:   PetscFunctionBegin;
    9520:   if (!nO) {
    9521:     *ornt  = 0;
    9522:     *found = PETSC_TRUE;
    9523:     PetscFunctionReturn(PETSC_SUCCESS);
    9524:   }
    9525:   for (o = -nO; o < nO; ++o) {
    9526:     const PetscInt *arr = DMPolytopeTypeGetArrangement(ct, o);

    9528:     for (c = 0; c < cS; ++c)
    9529:       if (sourceCone[arr[c * 2]] != targetCone[c]) break;
    9530:     if (c == cS) {
    9531:       *ornt = o;
    9532:       break;
    9533:     }
    9534:   }
    9535:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9536:   PetscFunctionReturn(PETSC_SUCCESS);
    9537: }

    9539: /*@
    9540:   DMPolytopeGetOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9542:   Not Collective

    9544:   Input Parameters:
    9545: + ct         - The `DMPolytopeType`
    9546: . sourceCone - The source arrangement of faces
    9547: - targetCone - The target arrangement of faces

    9549:   Output Parameter:
    9550: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9552:   Level: advanced

    9554:   Note:
    9555:   This function is the same as `DMPolytopeMatchOrientation()` except it will generate an error if no suitable orientation can be found.

    9557:   Developer Note:
    9558:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchOrientation()` and error if none is found

    9560: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchOrientation()`, `DMPolytopeGetVertexOrientation()`, `DMPolytopeMatchVertexOrientation()`
    9561: @*/
    9562: PetscErrorCode DMPolytopeGetOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9563: {
    9564:   PetscBool found;

    9566:   PetscFunctionBegin;
    9567:   PetscCall(DMPolytopeMatchOrientation(ct, sourceCone, targetCone, ornt, &found));
    9568:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9569:   PetscFunctionReturn(PETSC_SUCCESS);
    9570: }

    9572: /*@
    9573:   DMPolytopeMatchVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9575:   Not Collective

    9577:   Input Parameters:
    9578: + ct         - The `DMPolytopeType`
    9579: . sourceVert - The source arrangement of vertices
    9580: - targetVert - The target arrangement of vertices

    9582:   Output Parameters:
    9583: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9584: - found - Flag indicating that a suitable orientation was found

    9586:   Level: advanced

    9588:   Notes:
    9589:   An arrangement is a vertex order

    9591:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9592:   that labels each arrangement (vertex ordering).

    9594:   See `DMPolytopeMatchOrientation()` to find a new face orientation that takes the source face arrangement to the target face arrangement

    9596: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchOrientation()`, `DMPolytopeTypeGetNumVertices()`, `DMPolytopeTypeGetVertexArrangement()`
    9597: @*/
    9598: PetscErrorCode DMPolytopeMatchVertexOrientation(DMPolytopeType ct, const PetscInt sourceVert[], const PetscInt targetVert[], PetscInt *ornt, PetscBool *found)
    9599: {
    9600:   const PetscInt cS = DMPolytopeTypeGetNumVertices(ct);
    9601:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9602:   PetscInt       o, c;

    9604:   PetscFunctionBegin;
    9605:   if (!nO) {
    9606:     *ornt  = 0;
    9607:     *found = PETSC_TRUE;
    9608:     PetscFunctionReturn(PETSC_SUCCESS);
    9609:   }
    9610:   for (o = -nO; o < nO; ++o) {
    9611:     const PetscInt *arr = DMPolytopeTypeGetVertexArrangement(ct, o);

    9613:     for (c = 0; c < cS; ++c)
    9614:       if (sourceVert[arr[c]] != targetVert[c]) break;
    9615:     if (c == cS) {
    9616:       *ornt = o;
    9617:       break;
    9618:     }
    9619:   }
    9620:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9621:   PetscFunctionReturn(PETSC_SUCCESS);
    9622: }

    9624: /*@
    9625:   DMPolytopeGetVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9627:   Not Collective

    9629:   Input Parameters:
    9630: + ct         - The `DMPolytopeType`
    9631: . sourceCone - The source arrangement of vertices
    9632: - targetCone - The target arrangement of vertices

    9634:   Output Parameter:
    9635: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9637:   Level: advanced

    9639:   Note:
    9640:   This function is the same as `DMPolytopeMatchVertexOrientation()` except it errors if not orientation is possible.

    9642:   Developer Note:
    9643:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchVertexOrientation()` and error if none is found

    9645: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetOrientation()`
    9646: @*/
    9647: PetscErrorCode DMPolytopeGetVertexOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9648: {
    9649:   PetscBool found;

    9651:   PetscFunctionBegin;
    9652:   PetscCall(DMPolytopeMatchVertexOrientation(ct, sourceCone, targetCone, ornt, &found));
    9653:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9654:   PetscFunctionReturn(PETSC_SUCCESS);
    9655: }

    9657: /*@
    9658:   DMPolytopeInCellTest - Check whether a point lies inside the reference cell of given type

    9660:   Not Collective

    9662:   Input Parameters:
    9663: + ct    - The `DMPolytopeType`
    9664: - point - Coordinates of the point

    9666:   Output Parameter:
    9667: . inside - Flag indicating whether the point is inside the reference cell of given type

    9669:   Level: advanced

    9671: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMLocatePoints()`
    9672: @*/
    9673: PetscErrorCode DMPolytopeInCellTest(DMPolytopeType ct, const PetscReal point[], PetscBool *inside)
    9674: {
    9675:   PetscReal sum = 0.0;
    9676:   PetscInt  d;

    9678:   PetscFunctionBegin;
    9679:   *inside = PETSC_TRUE;
    9680:   switch (ct) {
    9681:   case DM_POLYTOPE_TRIANGLE:
    9682:   case DM_POLYTOPE_TETRAHEDRON:
    9683:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d) {
    9684:       if (point[d] < -1.0) {
    9685:         *inside = PETSC_FALSE;
    9686:         break;
    9687:       }
    9688:       sum += point[d];
    9689:     }
    9690:     if (sum > PETSC_SMALL) {
    9691:       *inside = PETSC_FALSE;
    9692:       break;
    9693:     }
    9694:     break;
    9695:   case DM_POLYTOPE_QUADRILATERAL:
    9696:   case DM_POLYTOPE_HEXAHEDRON:
    9697:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d)
    9698:       if (PetscAbsReal(point[d]) > 1. + PETSC_SMALL) {
    9699:         *inside = PETSC_FALSE;
    9700:         break;
    9701:       }
    9702:     break;
    9703:   default:
    9704:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported polytope type %s", DMPolytopeTypes[ct]);
    9705:   }
    9706:   PetscFunctionReturn(PETSC_SUCCESS);
    9707: }

    9709: /*@
    9710:   DMReorderSectionSetDefault - Set flag indicating whether the local section should be reordered by default

    9712:   Logically collective

    9714:   Input Parameters:
    9715: + dm      - The DM
    9716: - reorder - Flag for reordering

    9718:   Level: intermediate

    9720: .seealso: `DMReorderSectionGetDefault()`
    9721: @*/
    9722: PetscErrorCode DMReorderSectionSetDefault(DM dm, DMReorderDefaultFlag reorder)
    9723: {
    9724:   PetscFunctionBegin;
    9726:   PetscTryMethod(dm, "DMReorderSectionSetDefault_C", (DM, DMReorderDefaultFlag), (dm, reorder));
    9727:   PetscFunctionReturn(PETSC_SUCCESS);
    9728: }

    9730: /*@
    9731:   DMReorderSectionGetDefault - Get flag indicating whether the local section should be reordered by default

    9733:   Not collective

    9735:   Input Parameter:
    9736: . dm - The DM

    9738:   Output Parameter:
    9739: . reorder - Flag for reordering

    9741:   Level: intermediate

    9743: .seealso: `DMReorderSetDefault()`
    9744: @*/
    9745: PetscErrorCode DMReorderSectionGetDefault(DM dm, DMReorderDefaultFlag *reorder)
    9746: {
    9747:   PetscFunctionBegin;
    9749:   PetscAssertPointer(reorder, 2);
    9750:   *reorder = DM_REORDER_DEFAULT_NOTSET;
    9751:   PetscTryMethod(dm, "DMReorderSectionGetDefault_C", (DM, DMReorderDefaultFlag *), (dm, reorder));
    9752:   PetscFunctionReturn(PETSC_SUCCESS);
    9753: }

    9755: /*@
    9756:   DMReorderSectionSetType - Set the type of local section reordering

    9758:   Logically collective

    9760:   Input Parameters:
    9761: + dm      - The DM
    9762: - reorder - The reordering method

    9764:   Level: intermediate

    9766: .seealso: `DMReorderSectionGetType()`, `DMReorderSectionSetDefault()`
    9767: @*/
    9768: PetscErrorCode DMReorderSectionSetType(DM dm, MatOrderingType reorder)
    9769: {
    9770:   PetscFunctionBegin;
    9772:   PetscTryMethod(dm, "DMReorderSectionSetType_C", (DM, MatOrderingType), (dm, reorder));
    9773:   PetscFunctionReturn(PETSC_SUCCESS);
    9774: }

    9776: /*@
    9777:   DMReorderSectionGetType - Get the reordering type for the local section

    9779:   Not collective

    9781:   Input Parameter:
    9782: . dm - The DM

    9784:   Output Parameter:
    9785: . reorder - The reordering method

    9787:   Level: intermediate

    9789: .seealso: `DMReorderSetDefault()`, `DMReorderSectionGetDefault()`
    9790: @*/
    9791: PetscErrorCode DMReorderSectionGetType(DM dm, MatOrderingType *reorder)
    9792: {
    9793:   PetscFunctionBegin;
    9795:   PetscAssertPointer(reorder, 2);
    9796:   *reorder = NULL;
    9797:   PetscTryMethod(dm, "DMReorderSectionGetType_C", (DM, MatOrderingType *), (dm, reorder));
    9798:   PetscFunctionReturn(PETSC_SUCCESS);
    9799: }