Date: 2026-06-01T23:13:19+00:00

Actual source code: da3.c

      1: /*
      2:    Code for manipulating distributed regular 3d arrays in parallel.
      3:    File created by Peter Mell  7/14/95
      4:  */

      6: #include <petsc/private/dmdaimpl.h>

      8: #include <petscdraw.h>
      9: static PetscErrorCode DMView_DA_3d(DM da, PetscViewer viewer)
     10: {
     11:   PetscMPIInt rank;
     12:   PetscBool   isascii, isdraw, isglvis, isbinary;
     13:   DM_DA      *dd = (DM_DA *)da->data;
     14:   Vec         coordinates;
     15: #if defined(PETSC_HAVE_MATLAB)
     16:   PetscBool ismatlab;
     17: #endif

     19:   PetscFunctionBegin;
     20:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)da), &rank));

     22:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
     23:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
     24:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERGLVIS, &isglvis));
     25:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
     26: #if defined(PETSC_HAVE_MATLAB)
     27:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERMATLAB, &ismatlab));
     28: #endif
     29:   if (isascii) {
     30:     PetscViewerFormat format;

     32:     PetscCall(PetscViewerASCIIPushSynchronized(viewer));
     33:     PetscCall(PetscViewerGetFormat(viewer, &format));
     34:     if (format == PETSC_VIEWER_LOAD_BALANCE) {
     35:       PetscInt      i, nmax = 0, nmin = PETSC_INT_MAX, navg = 0, *nz, nzlocal;
     36:       DMDALocalInfo info;
     37:       PetscMPIInt   size;
     38:       PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)da), &size));
     39:       PetscCall(DMDAGetLocalInfo(da, &info));
     40:       nzlocal = info.xm * info.ym * info.zm;
     41:       PetscCall(PetscMalloc1(size, &nz));
     42:       PetscCallMPI(MPI_Allgather(&nzlocal, 1, MPIU_INT, nz, 1, MPIU_INT, PetscObjectComm((PetscObject)da)));
     43:       for (i = 0; i < size; i++) {
     44:         nmax = PetscMax(nmax, nz[i]);
     45:         nmin = PetscMin(nmin, nz[i]);
     46:         navg += nz[i];
     47:       }
     48:       PetscCall(PetscFree(nz));
     49:       navg = navg / size;
     50:       PetscCall(PetscViewerASCIIPrintf(viewer, "  Load Balance - Grid Points: Min %" PetscInt_FMT "  avg %" PetscInt_FMT "  max %" PetscInt_FMT "\n", nmin, navg, nmax));
     51:       PetscFunctionReturn(PETSC_SUCCESS);
     52:     }
     53:     if (format != PETSC_VIEWER_ASCII_GLVIS) {
     54:       DMDALocalInfo info;
     55:       PetscCall(DMDAGetLocalInfo(da, &info));
     56:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Processor [%d] M %" PetscInt_FMT " N %" PetscInt_FMT " P %" PetscInt_FMT " m %" PetscInt_FMT " n %" PetscInt_FMT " p %" PetscInt_FMT " w %" PetscInt_FMT " s %" PetscInt_FMT "\n", rank, dd->M, dd->N, dd->P, dd->m, dd->n, dd->p, dd->w, dd->s));
     57:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "X range of indices: %" PetscInt_FMT " %" PetscInt_FMT ", Y range of indices: %" PetscInt_FMT " %" PetscInt_FMT ", Z range of indices: %" PetscInt_FMT " %" PetscInt_FMT "\n", info.xs,
     58:                                                    info.xs + info.xm, info.ys, info.ys + info.ym, info.zs, info.zs + info.zm));
     59:       PetscCall(DMGetCoordinates(da, &coordinates));
     60: #if !defined(PETSC_USE_COMPLEX)
     61:       if (coordinates) {
     62:         PetscInt         last;
     63:         const PetscReal *coors;
     64:         PetscCall(VecGetArrayRead(coordinates, &coors));
     65:         PetscCall(VecGetLocalSize(coordinates, &last));
     66:         last = last - 3;
     67:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Lower left corner %g %g %g : Upper right %g %g %g\n", (double)coors[0], (double)coors[1], (double)coors[2], (double)coors[last], (double)coors[last + 1], (double)coors[last + 2]));
     68:         PetscCall(VecRestoreArrayRead(coordinates, &coors));
     69:       }
     70: #endif
     71:       PetscCall(PetscViewerFlush(viewer));
     72:       PetscCall(PetscViewerASCIIPopSynchronized(viewer));
     73:     } else if (format == PETSC_VIEWER_ASCII_GLVIS) PetscCall(DMView_DA_GLVis(da, viewer));
     74:   } else if (isdraw) {
     75:     PetscDraw       draw;
     76:     PetscReal       ymin = -1.0, ymax = (PetscReal)dd->N;
     77:     PetscReal       xmin = -1.0, xmax = (PetscReal)((dd->M + 2) * dd->P), x, y, ycoord, xcoord;
     78:     PetscInt        k, plane, base;
     79:     const PetscInt *idx;
     80:     char            node[10];
     81:     PetscBool       isnull;

     83:     PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
     84:     PetscCall(PetscDrawIsNull(draw, &isnull));
     85:     if (isnull) PetscFunctionReturn(PETSC_SUCCESS);

     87:     PetscCall(PetscDrawCheckResizedWindow(draw));
     88:     PetscCall(PetscDrawClear(draw));
     89:     PetscCall(PetscDrawSetCoordinates(draw, xmin, ymin, xmax, ymax));

     91:     PetscDrawCollectiveBegin(draw);
     92:     /* first processor draw all node lines */
     93:     if (rank == 0) {
     94:       for (k = 0; k < dd->P; k++) {
     95:         ymin = 0.0;
     96:         ymax = (PetscReal)(dd->N - 1);
     97:         for (xmin = (PetscReal)(k * (dd->M + 1)); xmin < (PetscReal)(dd->M + (k * (dd->M + 1))); xmin++) PetscCall(PetscDrawLine(draw, xmin, ymin, xmin, ymax, PETSC_DRAW_BLACK));
     98:         xmin = (PetscReal)(k * (dd->M + 1));
     99:         xmax = xmin + (PetscReal)(dd->M - 1);
    100:         for (ymin = 0; ymin < (PetscReal)dd->N; ymin++) PetscCall(PetscDrawLine(draw, xmin, ymin, xmax, ymin, PETSC_DRAW_BLACK));
    101:       }
    102:     }
    103:     PetscDrawCollectiveEnd(draw);
    104:     PetscCall(PetscDrawFlush(draw));
    105:     PetscCall(PetscDrawPause(draw));

    107:     PetscDrawCollectiveBegin(draw);
    108:     /*Go through and draw for each plane*/
    109:     for (k = 0; k < dd->P; k++) {
    110:       if ((k >= dd->zs) && (k < dd->ze)) {
    111:         /* draw my box */
    112:         ymin = dd->ys;
    113:         ymax = dd->ye - 1;
    114:         xmin = dd->xs / dd->w + (dd->M + 1) * k;
    115:         xmax = (dd->xe - 1) / dd->w + (dd->M + 1) * k;

    117:         PetscCall(PetscDrawLine(draw, xmin, ymin, xmax, ymin, PETSC_DRAW_RED));
    118:         PetscCall(PetscDrawLine(draw, xmin, ymin, xmin, ymax, PETSC_DRAW_RED));
    119:         PetscCall(PetscDrawLine(draw, xmin, ymax, xmax, ymax, PETSC_DRAW_RED));
    120:         PetscCall(PetscDrawLine(draw, xmax, ymin, xmax, ymax, PETSC_DRAW_RED));

    122:         xmin = dd->xs / dd->w;
    123:         xmax = (dd->xe - 1) / dd->w;

    125:         /* identify which processor owns the box */
    126:         PetscCall(PetscSNPrintf(node, sizeof(node), "%d", rank));
    127:         PetscCall(PetscDrawString(draw, xmin + (dd->M + 1) * k + .2, ymin + .3, PETSC_DRAW_RED, node));
    128:         /* put in numbers*/
    129:         base = (dd->base + (dd->xe - dd->xs) * (dd->ye - dd->ys) * (k - dd->zs)) / dd->w;
    130:         for (y = ymin; y <= ymax; y++) {
    131:           for (x = xmin + (dd->M + 1) * k; x <= xmax + (dd->M + 1) * k; x++) {
    132:             PetscCall(PetscSNPrintf(node, sizeof(node), "%" PetscInt_FMT, base++));
    133:             PetscCall(PetscDrawString(draw, x, y, PETSC_DRAW_BLACK, node));
    134:           }
    135:         }
    136:       }
    137:     }
    138:     PetscDrawCollectiveEnd(draw);
    139:     PetscCall(PetscDrawFlush(draw));
    140:     PetscCall(PetscDrawPause(draw));

    142:     PetscDrawCollectiveBegin(draw);
    143:     for (k = 0 - dd->s; k < dd->P + dd->s; k++) {
    144:       /* Go through and draw for each plane */
    145:       if ((k >= dd->Zs) && (k < dd->Ze)) {
    146:         /* overlay ghost numbers, useful for error checking */
    147:         base = (dd->Xe - dd->Xs) * (dd->Ye - dd->Ys) * (k - dd->Zs) / dd->w;
    148:         PetscCall(ISLocalToGlobalMappingGetBlockIndices(da->ltogmap, &idx));
    149:         plane = k;
    150:         /* Keep z wrap around points on the drawing */
    151:         if (k < 0) plane = dd->P + k;
    152:         if (k >= dd->P) plane = k - dd->P;
    153:         ymin = dd->Ys;
    154:         ymax = dd->Ye;
    155:         xmin = (dd->M + 1) * plane * dd->w;
    156:         xmax = (dd->M + 1) * plane * dd->w + dd->M * dd->w;
    157:         for (y = ymin; y < ymax; y++) {
    158:           for (x = xmin + dd->Xs; x < xmin + dd->Xe; x += dd->w) {
    159:             PetscCall(PetscSNPrintf(node, PETSC_STATIC_ARRAY_LENGTH(node), "%" PetscInt_FMT, idx[base]));
    160:             ycoord = y;
    161:             /*Keep y wrap around points on drawing */
    162:             if (y < 0) ycoord = dd->N + y;
    163:             if (y >= dd->N) ycoord = y - dd->N;
    164:             xcoord = x; /* Keep x wrap points on drawing */
    165:             if (x < xmin) xcoord = xmax - (xmin - x);
    166:             if (x >= xmax) xcoord = xmin + (x - xmax);
    167:             PetscCall(PetscDrawString(draw, xcoord / dd->w, ycoord, PETSC_DRAW_BLUE, node));
    168:             base++;
    169:           }
    170:         }
    171:         PetscCall(ISLocalToGlobalMappingRestoreBlockIndices(da->ltogmap, &idx));
    172:       }
    173:     }
    174:     PetscDrawCollectiveEnd(draw);
    175:     PetscCall(PetscDrawFlush(draw));
    176:     PetscCall(PetscDrawPause(draw));
    177:     PetscCall(PetscDrawSave(draw));
    178:   } else if (isglvis) {
    179:     PetscCall(DMView_DA_GLVis(da, viewer));
    180:   } else if (isbinary) {
    181:     PetscCall(DMView_DA_Binary(da, viewer));
    182: #if defined(PETSC_HAVE_MATLAB)
    183:   } else if (ismatlab) {
    184:     PetscCall(DMView_DA_Matlab(da, viewer));
    185: #endif
    186:   }
    187:   PetscFunctionReturn(PETSC_SUCCESS);
    188: }

    190: PetscErrorCode DMSetUp_DA_3D(DM da)
    191: {
    192:   DM_DA          *dd = (DM_DA *)da->data;
    193:   const PetscInt  M  = dd->M;
    194:   const PetscInt  N  = dd->N;
    195:   const PetscInt  P  = dd->P;
    196:   PetscMPIInt     m, n, p;
    197:   const PetscInt  dof          = dd->w;
    198:   const PetscInt  s            = dd->s;
    199:   DMBoundaryType  bx           = dd->bx;
    200:   DMBoundaryType  by           = dd->by;
    201:   DMBoundaryType  bz           = dd->bz;
    202:   DMDAStencilType stencil_type = dd->stencil_type;
    203:   PetscInt       *lx           = dd->lx;
    204:   PetscInt       *ly           = dd->ly;
    205:   PetscInt       *lz           = dd->lz;
    206:   MPI_Comm        comm;
    207:   PetscMPIInt     rank, size;
    208:   PetscInt        xs = 0, xe, ys = 0, ye, zs = 0, ze, x = 0, y = 0, z = 0;
    209:   PetscInt        Xs, Xe, Ys, Ye, Zs, Ze, IXs, IXe, IYs, IYe, IZs, IZe, pm;
    210:   PetscInt        left, right, up, down, bottom, top, i, j, k, *idx, nn;
    211:   PetscMPIInt     n0, n1, n2, n3, n4, n5, n6, n7, n8, n9, n10, n11, n12, n14;
    212:   PetscMPIInt     n15, n16, n17, n18, n19, n20, n21, n22, n23, n24, n25, n26;
    213:   PetscInt       *bases, *ldims, base, x_t, y_t, z_t, s_t, count, s_x, s_y, s_z;
    214:   PetscMPIInt     sn0 = 0, sn1 = 0, sn2 = 0, sn3 = 0, sn5 = 0, sn6 = 0, sn7 = 0;
    215:   PetscMPIInt     sn8 = 0, sn9 = 0, sn11 = 0, sn15 = 0, sn24 = 0, sn25 = 0, sn26 = 0;
    216:   PetscMPIInt     sn17 = 0, sn18 = 0, sn19 = 0, sn20 = 0, sn21 = 0, sn23 = 0;
    217:   Vec             local, global;
    218:   VecScatter      gtol;
    219:   IS              to, from;
    220:   PetscBool       twod;

    222:   PetscFunctionBegin;
    223:   PetscCheck(stencil_type != DMDA_STENCIL_BOX || (bx != DM_BOUNDARY_MIRROR && by != DM_BOUNDARY_MIRROR && bz != DM_BOUNDARY_MIRROR), PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Mirror boundary and box stencil");
    224:   PetscCall(PetscObjectGetComm((PetscObject)da, &comm));
    225: #if !defined(PETSC_USE_64BIT_INDICES)
    226:   PetscCheck(((PetscInt64)M) * ((PetscInt64)N) * ((PetscInt64)P) * ((PetscInt64)dof) <= (PetscInt64)PETSC_MPI_INT_MAX, comm, PETSC_ERR_INT_OVERFLOW, "Mesh of %" PetscInt_FMT " by %" PetscInt_FMT " by %" PetscInt_FMT " by %" PetscInt_FMT " (dof) is too large for 32-bit indices", M, N, P, dof);
    227: #endif
    228:   PetscCall(PetscMPIIntCast(dd->m, &m));
    229:   PetscCall(PetscMPIIntCast(dd->n, &n));
    230:   PetscCall(PetscMPIIntCast(dd->p, &p));

    232:   PetscCallMPI(MPI_Comm_size(comm, &size));
    233:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

    235:   if (m != PETSC_DECIDE) {
    236:     PetscCheck(m >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Non-positive number of processors in X direction: %d", m);
    237:     PetscCheck(m <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many processors in X direction: %d %d", m, size);
    238:   }
    239:   if (n != PETSC_DECIDE) {
    240:     PetscCheck(n >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Non-positive number of processors in Y direction: %d", n);
    241:     PetscCheck(n <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many processors in Y direction: %d %d", n, size);
    242:   }
    243:   if (p != PETSC_DECIDE) {
    244:     PetscCheck(p >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Non-positive number of processors in Z direction: %d", p);
    245:     PetscCheck(p <= size, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many processors in Z direction: %d %d", p, size);
    246:   }
    247:   PetscCheck(m <= 0 || n <= 0 || p <= 0 || m * n * p == size, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "m %d * n %d * p %d != size %d", m, n, p, size);

    249:   /* Partition the array among the processors */
    250:   if (m == PETSC_DECIDE && n != PETSC_DECIDE && p != PETSC_DECIDE) {
    251:     m = size / (n * p);
    252:   } else if (m != PETSC_DECIDE && n == PETSC_DECIDE && p != PETSC_DECIDE) {
    253:     n = size / (m * p);
    254:   } else if (m != PETSC_DECIDE && n != PETSC_DECIDE && p == PETSC_DECIDE) {
    255:     p = size / (m * n);
    256:   } else if (m == PETSC_DECIDE && n == PETSC_DECIDE && p != PETSC_DECIDE) {
    257:     /* try for squarish distribution */
    258:     m = (int)(0.5 + PetscSqrtReal(((PetscReal)M) * ((PetscReal)size) / ((PetscReal)N * p)));
    259:     if (!m) m = 1;
    260:     while (m > 0) {
    261:       n = size / (m * p);
    262:       if (m * n * p == size) break;
    263:       m--;
    264:     }
    265:     PetscCheck(m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "bad p value: p = %d", p);
    266:     if (M > N && m < n) {
    267:       PetscMPIInt _m = m;
    268:       m              = n;
    269:       n              = _m;
    270:     }
    271:   } else if (m == PETSC_DECIDE && n != PETSC_DECIDE && p == PETSC_DECIDE) {
    272:     /* try for squarish distribution */
    273:     m = (int)(0.5 + PetscSqrtReal(((PetscReal)M) * ((PetscReal)size) / ((PetscReal)P * n)));
    274:     if (!m) m = 1;
    275:     while (m > 0) {
    276:       p = size / (m * n);
    277:       if (m * n * p == size) break;
    278:       m--;
    279:     }
    280:     PetscCheck(m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "bad n value: n = %d", n);
    281:     if (M > P && m < p) {
    282:       PetscMPIInt _m = m;
    283:       m              = p;
    284:       p              = _m;
    285:     }
    286:   } else if (m != PETSC_DECIDE && n == PETSC_DECIDE && p == PETSC_DECIDE) {
    287:     /* try for squarish distribution */
    288:     n = (int)(0.5 + PetscSqrtReal(((PetscReal)N) * ((PetscReal)size) / ((PetscReal)P * m)));
    289:     if (!n) n = 1;
    290:     while (n > 0) {
    291:       p = size / (m * n);
    292:       if (m * n * p == size) break;
    293:       n--;
    294:     }
    295:     PetscCheck(n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "bad m value: m = %d", n);
    296:     if (N > P && n < p) {
    297:       PetscMPIInt _n = n;
    298:       n              = p;
    299:       p              = _n;
    300:     }
    301:   } else if (m == PETSC_DECIDE && n == PETSC_DECIDE && p == PETSC_DECIDE) {
    302:     /* try for squarish distribution */
    303:     n = (PetscMPIInt)(0.5 + PetscPowReal(((PetscReal)N * N) * ((PetscReal)size) / ((PetscReal)P * M), (PetscReal)(1. / 3.)));
    304:     if (!n) n = 1;
    305:     while (n > 0) {
    306:       pm = size / n;
    307:       if (n * pm == size) break;
    308:       n--;
    309:     }
    310:     if (!n) n = 1;
    311:     m = (PetscMPIInt)(0.5 + PetscSqrtReal(((PetscReal)M) * ((PetscReal)size) / ((PetscReal)P * n)));
    312:     if (!m) m = 1;
    313:     while (m > 0) {
    314:       p = size / (m * n);
    315:       if (m * n * p == size) break;
    316:       m--;
    317:     }
    318:     if (M > P && m < p) {
    319:       PetscMPIInt _m = m;
    320:       m              = p;
    321:       p              = _m;
    322:     }
    323:   } else PetscCheck(m * n * p == size, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Given Bad partition");

    325:   PetscCheck(m * n * p == size, PetscObjectComm((PetscObject)da), PETSC_ERR_PLIB, "Could not find good partition");
    326:   PetscCheck(M >= m, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Partition in x direction is too fine! %" PetscInt_FMT " %d", M, m);
    327:   PetscCheck(N >= n, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Partition in y direction is too fine! %" PetscInt_FMT " %d", N, n);
    328:   PetscCheck(P >= p, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_OUTOFRANGE, "Partition in z direction is too fine! %" PetscInt_FMT " %d", P, p);

    330:   /*
    331:      Determine locally owned region
    332:      [x, y, or z]s is the first local node number, [x, y, z] is the number of local nodes
    333:   */

    335:   if (!lx) {
    336:     PetscCall(PetscMalloc1(m, &dd->lx));
    337:     lx = dd->lx;
    338:     for (i = 0; i < m; i++) lx[i] = M / m + ((M % m) > (i % m));
    339:   }
    340:   x  = lx[rank % m];
    341:   xs = 0;
    342:   for (i = 0; i < (rank % m); i++) xs += lx[i];
    343:   PetscCheck(x >= s || (m <= 1 && bx != DM_BOUNDARY_PERIODIC), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local x-width of domain x %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT, x, s);

    345:   if (!ly) {
    346:     PetscCall(PetscMalloc1(n, &dd->ly));
    347:     ly = dd->ly;
    348:     for (i = 0; i < n; i++) ly[i] = N / n + ((N % n) > (i % n));
    349:   }
    350:   y = ly[(rank % (m * n)) / m];
    351:   PetscCheck(y >= s || (n <= 1 && by != DM_BOUNDARY_PERIODIC), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local y-width of domain y %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT, y, s);

    353:   ys = 0;
    354:   for (i = 0; i < (rank % (m * n)) / m; i++) ys += ly[i];

    356:   if (!lz) {
    357:     PetscCall(PetscMalloc1(p, &dd->lz));
    358:     lz = dd->lz;
    359:     for (i = 0; i < p; i++) lz[i] = P / p + ((P % p) > (i % p));
    360:   }
    361:   z = lz[rank / (m * n)];

    363:   PetscCheck((x > s) || (bx != DM_BOUNDARY_MIRROR), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local x-width of domain x %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT " with mirror", x, s);
    364:   PetscCheck((y > s) || (by != DM_BOUNDARY_MIRROR), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local y-width of domain y %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT " with mirror", y, s);
    365:   PetscCheck((z > s) || (bz != DM_BOUNDARY_MIRROR), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local z-width of domain z %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT " with mirror", z, s);

    367:   /* note this is different than x- and y-, as we will handle as an important special
    368:    case when p=P=1 and DM_BOUNDARY_PERIODIC and s > z.  This is to deal with 2D problems
    369:    in a 3D code.  Additional code for this case is noted with "2d case" comments */
    370:   twod = PETSC_FALSE;
    371:   if (P == 1) twod = PETSC_TRUE;
    372:   else PetscCheck(z >= s || (p <= 1 && bz != DM_BOUNDARY_PERIODIC), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local z-width of domain z %" PetscInt_FMT " is smaller than stencil width s %" PetscInt_FMT, z, s);
    373:   zs = 0;
    374:   for (i = 0; i < (rank / (m * n)); i++) zs += lz[i];
    375:   ye = ys + y;
    376:   xe = xs + x;
    377:   ze = zs + z;

    379:   /* determine ghost region (Xs) and region scattered into (IXs)  */
    380:   if (xs - s > 0) {
    381:     Xs  = xs - s;
    382:     IXs = xs - s;
    383:   } else {
    384:     if (bx) Xs = xs - s;
    385:     else Xs = 0;
    386:     IXs = 0;
    387:   }
    388:   if (xe + s <= M) {
    389:     Xe  = xe + s;
    390:     IXe = xe + s;
    391:   } else {
    392:     if (bx) {
    393:       Xs = xs - s;
    394:       Xe = xe + s;
    395:     } else Xe = M;
    396:     IXe = M;
    397:   }

    399:   if (bx == DM_BOUNDARY_PERIODIC || bx == DM_BOUNDARY_MIRROR) {
    400:     IXs = xs - s;
    401:     IXe = xe + s;
    402:     Xs  = xs - s;
    403:     Xe  = xe + s;
    404:   }

    406:   if (ys - s > 0) {
    407:     Ys  = ys - s;
    408:     IYs = ys - s;
    409:   } else {
    410:     if (by) Ys = ys - s;
    411:     else Ys = 0;
    412:     IYs = 0;
    413:   }
    414:   if (ye + s <= N) {
    415:     Ye  = ye + s;
    416:     IYe = ye + s;
    417:   } else {
    418:     if (by) Ye = ye + s;
    419:     else Ye = N;
    420:     IYe = N;
    421:   }

    423:   if (by == DM_BOUNDARY_PERIODIC || by == DM_BOUNDARY_MIRROR) {
    424:     IYs = ys - s;
    425:     IYe = ye + s;
    426:     Ys  = ys - s;
    427:     Ye  = ye + s;
    428:   }

    430:   if (zs - s > 0) {
    431:     Zs  = zs - s;
    432:     IZs = zs - s;
    433:   } else {
    434:     if (bz) Zs = zs - s;
    435:     else Zs = 0;
    436:     IZs = 0;
    437:   }
    438:   if (ze + s <= P) {
    439:     Ze  = ze + s;
    440:     IZe = ze + s;
    441:   } else {
    442:     if (bz) Ze = ze + s;
    443:     else Ze = P;
    444:     IZe = P;
    445:   }

    447:   if (bz == DM_BOUNDARY_PERIODIC || bz == DM_BOUNDARY_MIRROR) {
    448:     IZs = zs - s;
    449:     IZe = ze + s;
    450:     Zs  = zs - s;
    451:     Ze  = ze + s;
    452:   }

    454:   /* Resize all X parameters to reflect w */
    455:   s_x = s;
    456:   s_y = s;
    457:   s_z = s;

    459:   /* determine starting point of each processor */
    460:   nn = x * y * z;
    461:   PetscCall(PetscMalloc2(size + 1, &bases, size, &ldims));
    462:   PetscCallMPI(MPI_Allgather(&nn, 1, MPIU_INT, ldims, 1, MPIU_INT, comm));
    463:   bases[0] = 0;
    464:   for (i = 1; i <= size; i++) bases[i] = ldims[i - 1];
    465:   for (i = 1; i <= size; i++) bases[i] += bases[i - 1];
    466:   base = bases[rank] * dof;

    468:   /* allocate the base parallel and sequential vectors */
    469:   dd->Nlocal = x * y * z * dof;
    470:   PetscCall(VecCreateMPIWithArray(comm, dof, dd->Nlocal, PETSC_DECIDE, NULL, &global));
    471:   dd->nlocal = (Xe - Xs) * (Ye - Ys) * (Ze - Zs) * dof;
    472:   PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, dof, dd->nlocal, NULL, &local));

    474:   /* generate global to local vector scatter and local to global mapping*/

    476:   /* global to local must include ghost points within the domain,
    477:      but not ghost points outside the domain that aren't periodic */
    478:   PetscCall(PetscMalloc1((IXe - IXs) * (IYe - IYs) * (IZe - IZs), &idx));
    479:   if (stencil_type == DMDA_STENCIL_BOX) {
    480:     left   = IXs - Xs;
    481:     right  = left + (IXe - IXs);
    482:     bottom = IYs - Ys;
    483:     top    = bottom + (IYe - IYs);
    484:     down   = IZs - Zs;
    485:     up     = down + (IZe - IZs);
    486:     count  = 0;
    487:     for (i = down; i < up; i++) {
    488:       for (j = bottom; j < top; j++) {
    489:         for (k = left; k < right; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    490:       }
    491:     }
    492:     PetscCall(ISCreateBlock(comm, dof, count, idx, PETSC_OWN_POINTER, &to));
    493:   } else {
    494:     /* This is way ugly! We need to list the funny cross type region */
    495:     left   = xs - Xs;
    496:     right  = left + x;
    497:     bottom = ys - Ys;
    498:     top    = bottom + y;
    499:     down   = zs - Zs;
    500:     up     = down + z;
    501:     count  = 0;
    502:     /* the bottom chunk */
    503:     for (i = (IZs - Zs); i < down; i++) {
    504:       for (j = bottom; j < top; j++) {
    505:         for (k = left; k < right; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    506:       }
    507:     }
    508:     /* the middle piece */
    509:     for (i = down; i < up; i++) {
    510:       /* front */
    511:       for (j = (IYs - Ys); j < bottom; j++) {
    512:         for (k = left; k < right; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    513:       }
    514:       /* middle */
    515:       for (j = bottom; j < top; j++) {
    516:         for (k = IXs - Xs; k < IXe - Xs; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    517:       }
    518:       /* back */
    519:       for (j = top; j < top + IYe - ye; j++) {
    520:         for (k = left; k < right; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    521:       }
    522:     }
    523:     /* the top piece */
    524:     for (i = up; i < up + IZe - ze; i++) {
    525:       for (j = bottom; j < top; j++) {
    526:         for (k = left; k < right; k++) idx[count++] = (i * (Ye - Ys) + j) * (Xe - Xs) + k;
    527:       }
    528:     }
    529:     PetscCall(ISCreateBlock(comm, dof, count, idx, PETSC_OWN_POINTER, &to));
    530:   }

    532:   /* determine who lies on each side of use stored in    n24 n25 n26
    533:                                                          n21 n22 n23
    534:                                                          n18 n19 n20

    536:                                                          n15 n16 n17
    537:                                                          n12     n14
    538:                                                          n9  n10 n11

    540:                                                          n6  n7  n8
    541:                                                          n3  n4  n5
    542:                                                          n0  n1  n2
    543:   */

    545:   /* Solve for X,Y, and Z Periodic Case First, Then Modify Solution */
    546:   /* Assume Nodes are Internal to the Cube */
    547:   n0 = rank - m * n - m - 1;
    548:   n1 = rank - m * n - m;
    549:   n2 = rank - m * n - m + 1;
    550:   n3 = rank - m * n - 1;
    551:   n4 = rank - m * n;
    552:   n5 = rank - m * n + 1;
    553:   n6 = rank - m * n + m - 1;
    554:   n7 = rank - m * n + m;
    555:   n8 = rank - m * n + m + 1;

    557:   n9  = rank - m - 1;
    558:   n10 = rank - m;
    559:   n11 = rank - m + 1;
    560:   n12 = rank - 1;
    561:   n14 = rank + 1;
    562:   n15 = rank + m - 1;
    563:   n16 = rank + m;
    564:   n17 = rank + m + 1;

    566:   n18 = rank + m * n - m - 1;
    567:   n19 = rank + m * n - m;
    568:   n20 = rank + m * n - m + 1;
    569:   n21 = rank + m * n - 1;
    570:   n22 = rank + m * n;
    571:   n23 = rank + m * n + 1;
    572:   n24 = rank + m * n + m - 1;
    573:   n25 = rank + m * n + m;
    574:   n26 = rank + m * n + m + 1;

    576:   /* Assume Pieces are on Faces of Cube */

    578:   if (xs == 0) { /* First assume not corner or edge */
    579:     n0  = rank - 1 - (m * n);
    580:     n3  = rank + m - 1 - (m * n);
    581:     n6  = rank + 2 * m - 1 - (m * n);
    582:     n9  = rank - 1;
    583:     n12 = rank + m - 1;
    584:     n15 = rank + 2 * m - 1;
    585:     n18 = rank - 1 + (m * n);
    586:     n21 = rank + m - 1 + (m * n);
    587:     n24 = rank + 2 * m - 1 + (m * n);
    588:   }

    590:   if (xe == M) { /* First assume not corner or edge */
    591:     n2  = rank - 2 * m + 1 - (m * n);
    592:     n5  = rank - m + 1 - (m * n);
    593:     n8  = rank + 1 - (m * n);
    594:     n11 = rank - 2 * m + 1;
    595:     n14 = rank - m + 1;
    596:     n17 = rank + 1;
    597:     n20 = rank - 2 * m + 1 + (m * n);
    598:     n23 = rank - m + 1 + (m * n);
    599:     n26 = rank + 1 + (m * n);
    600:   }

    602:   if (ys == 0) { /* First assume not corner or edge */
    603:     n0  = rank + m * (n - 1) - 1 - (m * n);
    604:     n1  = rank + m * (n - 1) - (m * n);
    605:     n2  = rank + m * (n - 1) + 1 - (m * n);
    606:     n9  = rank + m * (n - 1) - 1;
    607:     n10 = rank + m * (n - 1);
    608:     n11 = rank + m * (n - 1) + 1;
    609:     n18 = rank + m * (n - 1) - 1 + (m * n);
    610:     n19 = rank + m * (n - 1) + (m * n);
    611:     n20 = rank + m * (n - 1) + 1 + (m * n);
    612:   }

    614:   if (ye == N) { /* First assume not corner or edge */
    615:     n6  = rank - m * (n - 1) - 1 - (m * n);
    616:     n7  = rank - m * (n - 1) - (m * n);
    617:     n8  = rank - m * (n - 1) + 1 - (m * n);
    618:     n15 = rank - m * (n - 1) - 1;
    619:     n16 = rank - m * (n - 1);
    620:     n17 = rank - m * (n - 1) + 1;
    621:     n24 = rank - m * (n - 1) - 1 + (m * n);
    622:     n25 = rank - m * (n - 1) + (m * n);
    623:     n26 = rank - m * (n - 1) + 1 + (m * n);
    624:   }

    626:   if (zs == 0) { /* First assume not corner or edge */
    627:     n0 = size - (m * n) + rank - m - 1;
    628:     n1 = size - (m * n) + rank - m;
    629:     n2 = size - (m * n) + rank - m + 1;
    630:     n3 = size - (m * n) + rank - 1;
    631:     n4 = size - (m * n) + rank;
    632:     n5 = size - (m * n) + rank + 1;
    633:     n6 = size - (m * n) + rank + m - 1;
    634:     n7 = size - (m * n) + rank + m;
    635:     n8 = size - (m * n) + rank + m + 1;
    636:   }

    638:   if (ze == P) { /* First assume not corner or edge */
    639:     n18 = (m * n) - (size - rank) - m - 1;
    640:     n19 = (m * n) - (size - rank) - m;
    641:     n20 = (m * n) - (size - rank) - m + 1;
    642:     n21 = (m * n) - (size - rank) - 1;
    643:     n22 = (m * n) - (size - rank);
    644:     n23 = (m * n) - (size - rank) + 1;
    645:     n24 = (m * n) - (size - rank) + m - 1;
    646:     n25 = (m * n) - (size - rank) + m;
    647:     n26 = (m * n) - (size - rank) + m + 1;
    648:   }

    650:   if ((xs == 0) && (zs == 0)) { /* Assume an edge, not corner */
    651:     n0 = size - m * n + rank + m - 1 - m;
    652:     n3 = size - m * n + rank + m - 1;
    653:     n6 = size - m * n + rank + m - 1 + m;
    654:   }

    656:   if ((xs == 0) && (ze == P)) { /* Assume an edge, not corner */
    657:     n18 = m * n - (size - rank) + m - 1 - m;
    658:     n21 = m * n - (size - rank) + m - 1;
    659:     n24 = m * n - (size - rank) + m - 1 + m;
    660:   }

    662:   if ((xs == 0) && (ys == 0)) { /* Assume an edge, not corner */
    663:     n0  = rank + m * n - 1 - m * n;
    664:     n9  = rank + m * n - 1;
    665:     n18 = rank + m * n - 1 + m * n;
    666:   }

    668:   if ((xs == 0) && (ye == N)) { /* Assume an edge, not corner */
    669:     n6  = rank - m * (n - 1) + m - 1 - m * n;
    670:     n15 = rank - m * (n - 1) + m - 1;
    671:     n24 = rank - m * (n - 1) + m - 1 + m * n;
    672:   }

    674:   if ((xe == M) && (zs == 0)) { /* Assume an edge, not corner */
    675:     n2 = size - (m * n - rank) - (m - 1) - m;
    676:     n5 = size - (m * n - rank) - (m - 1);
    677:     n8 = size - (m * n - rank) - (m - 1) + m;
    678:   }

    680:   if ((xe == M) && (ze == P)) { /* Assume an edge, not corner */
    681:     n20 = m * n - (size - rank) - (m - 1) - m;
    682:     n23 = m * n - (size - rank) - (m - 1);
    683:     n26 = m * n - (size - rank) - (m - 1) + m;
    684:   }

    686:   if ((xe == M) && (ys == 0)) { /* Assume an edge, not corner */
    687:     n2  = rank + m * (n - 1) - (m - 1) - m * n;
    688:     n11 = rank + m * (n - 1) - (m - 1);
    689:     n20 = rank + m * (n - 1) - (m - 1) + m * n;
    690:   }

    692:   if ((xe == M) && (ye == N)) { /* Assume an edge, not corner */
    693:     n8  = rank - m * n + 1 - m * n;
    694:     n17 = rank - m * n + 1;
    695:     n26 = rank - m * n + 1 + m * n;
    696:   }

    698:   if ((ys == 0) && (zs == 0)) { /* Assume an edge, not corner */
    699:     n0 = size - m + rank - 1;
    700:     n1 = size - m + rank;
    701:     n2 = size - m + rank + 1;
    702:   }

    704:   if ((ys == 0) && (ze == P)) { /* Assume an edge, not corner */
    705:     n18 = m * n - (size - rank) + m * (n - 1) - 1;
    706:     n19 = m * n - (size - rank) + m * (n - 1);
    707:     n20 = m * n - (size - rank) + m * (n - 1) + 1;
    708:   }

    710:   if ((ye == N) && (zs == 0)) { /* Assume an edge, not corner */
    711:     n6 = size - (m * n - rank) - m * (n - 1) - 1;
    712:     n7 = size - (m * n - rank) - m * (n - 1);
    713:     n8 = size - (m * n - rank) - m * (n - 1) + 1;
    714:   }

    716:   if ((ye == N) && (ze == P)) { /* Assume an edge, not corner */
    717:     n24 = rank - (size - m) - 1;
    718:     n25 = rank - (size - m);
    719:     n26 = rank - (size - m) + 1;
    720:   }

    722:   /* Check for Corners */
    723:   if ((xs == 0) && (ys == 0) && (zs == 0)) n0 = size - 1;
    724:   if ((xs == 0) && (ys == 0) && (ze == P)) n18 = m * n - 1;
    725:   if ((xs == 0) && (ye == N) && (zs == 0)) n6 = (size - 1) - m * (n - 1);
    726:   if ((xs == 0) && (ye == N) && (ze == P)) n24 = m - 1;
    727:   if ((xe == M) && (ys == 0) && (zs == 0)) n2 = size - m;
    728:   if ((xe == M) && (ys == 0) && (ze == P)) n20 = m * n - m;
    729:   if ((xe == M) && (ye == N) && (zs == 0)) n8 = size - m * n;
    730:   if ((xe == M) && (ye == N) && (ze == P)) n26 = 0;

    732:   /* Check for when not X,Y, and Z Periodic */

    734:   /* If not X periodic */
    735:   if (bx != DM_BOUNDARY_PERIODIC) {
    736:     if (xs == 0) n0 = n3 = n6 = n9 = n12 = n15 = n18 = n21 = n24 = -2;
    737:     if (xe == M) n2 = n5 = n8 = n11 = n14 = n17 = n20 = n23 = n26 = -2;
    738:   }

    740:   /* If not Y periodic */
    741:   if (by != DM_BOUNDARY_PERIODIC) {
    742:     if (ys == 0) n0 = n1 = n2 = n9 = n10 = n11 = n18 = n19 = n20 = -2;
    743:     if (ye == N) n6 = n7 = n8 = n15 = n16 = n17 = n24 = n25 = n26 = -2;
    744:   }

    746:   /* If not Z periodic */
    747:   if (bz != DM_BOUNDARY_PERIODIC) {
    748:     if (zs == 0) n0 = n1 = n2 = n3 = n4 = n5 = n6 = n7 = n8 = -2;
    749:     if (ze == P) n18 = n19 = n20 = n21 = n22 = n23 = n24 = n25 = n26 = -2;
    750:   }

    752:   PetscCall(PetscMalloc1(27, &dd->neighbors));

    754:   dd->neighbors[0]  = n0;
    755:   dd->neighbors[1]  = n1;
    756:   dd->neighbors[2]  = n2;
    757:   dd->neighbors[3]  = n3;
    758:   dd->neighbors[4]  = n4;
    759:   dd->neighbors[5]  = n5;
    760:   dd->neighbors[6]  = n6;
    761:   dd->neighbors[7]  = n7;
    762:   dd->neighbors[8]  = n8;
    763:   dd->neighbors[9]  = n9;
    764:   dd->neighbors[10] = n10;
    765:   dd->neighbors[11] = n11;
    766:   dd->neighbors[12] = n12;
    767:   dd->neighbors[13] = rank;
    768:   dd->neighbors[14] = n14;
    769:   dd->neighbors[15] = n15;
    770:   dd->neighbors[16] = n16;
    771:   dd->neighbors[17] = n17;
    772:   dd->neighbors[18] = n18;
    773:   dd->neighbors[19] = n19;
    774:   dd->neighbors[20] = n20;
    775:   dd->neighbors[21] = n21;
    776:   dd->neighbors[22] = n22;
    777:   dd->neighbors[23] = n23;
    778:   dd->neighbors[24] = n24;
    779:   dd->neighbors[25] = n25;
    780:   dd->neighbors[26] = n26;

    782:   /* If star stencil then delete the corner neighbors */
    783:   if (stencil_type == DMDA_STENCIL_STAR) {
    784:     /* save information about corner neighbors */
    785:     sn0  = n0;
    786:     sn1  = n1;
    787:     sn2  = n2;
    788:     sn3  = n3;
    789:     sn5  = n5;
    790:     sn6  = n6;
    791:     sn7  = n7;
    792:     sn8  = n8;
    793:     sn9  = n9;
    794:     sn11 = n11;
    795:     sn15 = n15;
    796:     sn17 = n17;
    797:     sn18 = n18;
    798:     sn19 = n19;
    799:     sn20 = n20;
    800:     sn21 = n21;
    801:     sn23 = n23;
    802:     sn24 = n24;
    803:     sn25 = n25;
    804:     sn26 = n26;
    805:     n0 = n1 = n2 = n3 = n5 = n6 = n7 = n8 = n9 = n11 = n15 = n17 = n18 = n19 = n20 = n21 = n23 = n24 = n25 = n26 = -1;
    806:   }

    808:   PetscCall(PetscMalloc1((Xe - Xs) * (Ye - Ys) * (Ze - Zs), &idx));

    810:   nn = 0;
    811:   /* Bottom Level */
    812:   for (k = 0; k < s_z; k++) {
    813:     for (i = 1; i <= s_y; i++) {
    814:       if (n0 >= 0) { /* left below */
    815:         x_t = lx[n0 % m];
    816:         y_t = ly[(n0 % (m * n)) / m];
    817:         z_t = lz[n0 / (m * n)];
    818:         s_t = bases[n0] + x_t * y_t * z_t - (s_y - i) * x_t - s_x - (s_z - k - 1) * x_t * y_t;
    819:         if (twod && (s_t < 0)) s_t = bases[n0] + x_t * y_t * z_t - (s_y - i) * x_t - s_x; /* 2D case */
    820:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    821:       }
    822:       if (n1 >= 0) { /* directly below */
    823:         x_t = x;
    824:         y_t = ly[(n1 % (m * n)) / m];
    825:         z_t = lz[n1 / (m * n)];
    826:         s_t = bases[n1] + x_t * y_t * z_t - (s_y + 1 - i) * x_t - (s_z - k - 1) * x_t * y_t;
    827:         if (twod && (s_t < 0)) s_t = bases[n1] + x_t * y_t * z_t - (s_y + 1 - i) * x_t; /* 2D case */
    828:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    829:       }
    830:       if (n2 >= 0) { /* right below */
    831:         x_t = lx[n2 % m];
    832:         y_t = ly[(n2 % (m * n)) / m];
    833:         z_t = lz[n2 / (m * n)];
    834:         s_t = bases[n2] + x_t * y_t * z_t - (s_y + 1 - i) * x_t - (s_z - k - 1) * x_t * y_t;
    835:         if (twod && (s_t < 0)) s_t = bases[n2] + x_t * y_t * z_t - (s_y + 1 - i) * x_t; /* 2D case */
    836:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    837:       }
    838:     }

    840:     for (i = 0; i < y; i++) {
    841:       if (n3 >= 0) { /* directly left */
    842:         x_t = lx[n3 % m];
    843:         y_t = y;
    844:         z_t = lz[n3 / (m * n)];
    845:         s_t = bases[n3] + (i + 1) * x_t - s_x + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    846:         if (twod && (s_t < 0)) s_t = bases[n3] + (i + 1) * x_t - s_x + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    847:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    848:       }

    850:       if (n4 >= 0) { /* middle */
    851:         x_t = x;
    852:         y_t = y;
    853:         z_t = lz[n4 / (m * n)];
    854:         s_t = bases[n4] + i * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    855:         if (twod && (s_t < 0)) s_t = bases[n4] + i * x_t + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    856:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    857:       } else if (bz == DM_BOUNDARY_MIRROR) {
    858:         for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + x * i + (s_z - k - 1) * x * y;
    859:       }

    861:       if (n5 >= 0) { /* directly right */
    862:         x_t = lx[n5 % m];
    863:         y_t = y;
    864:         z_t = lz[n5 / (m * n)];
    865:         s_t = bases[n5] + i * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    866:         if (twod && (s_t < 0)) s_t = bases[n5] + i * x_t + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    867:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    868:       }
    869:     }

    871:     for (i = 1; i <= s_y; i++) {
    872:       if (n6 >= 0) { /* left above */
    873:         x_t = lx[n6 % m];
    874:         y_t = ly[(n6 % (m * n)) / m];
    875:         z_t = lz[n6 / (m * n)];
    876:         s_t = bases[n6] + i * x_t - s_x + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    877:         if (twod && (s_t < 0)) s_t = bases[n6] + i * x_t - s_x + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    878:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    879:       }
    880:       if (n7 >= 0) { /* directly above */
    881:         x_t = x;
    882:         y_t = ly[(n7 % (m * n)) / m];
    883:         z_t = lz[n7 / (m * n)];
    884:         s_t = bases[n7] + (i - 1) * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    885:         if (twod && (s_t < 0)) s_t = bases[n7] + (i - 1) * x_t + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    886:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    887:       }
    888:       if (n8 >= 0) { /* right above */
    889:         x_t = lx[n8 % m];
    890:         y_t = ly[(n8 % (m * n)) / m];
    891:         z_t = lz[n8 / (m * n)];
    892:         s_t = bases[n8] + (i - 1) * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    893:         if (twod && (s_t < 0)) s_t = bases[n8] + (i - 1) * x_t + x_t * y_t * z_t - x_t * y_t; /* 2D case */
    894:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    895:       }
    896:     }
    897:   }

    899:   /* Middle Level */
    900:   for (k = 0; k < z; k++) {
    901:     for (i = 1; i <= s_y; i++) {
    902:       if (n9 >= 0) { /* left below */
    903:         x_t = lx[n9 % m];
    904:         y_t = ly[(n9 % (m * n)) / m];
    905:         /* z_t = z; */
    906:         s_t = bases[n9] - (s_y - i) * x_t - s_x + (k + 1) * x_t * y_t;
    907:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    908:       }
    909:       if (n10 >= 0) { /* directly below */
    910:         x_t = x;
    911:         y_t = ly[(n10 % (m * n)) / m];
    912:         /* z_t = z; */
    913:         s_t = bases[n10] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    914:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    915:       } else if (by == DM_BOUNDARY_MIRROR) {
    916:         for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + k * x * y + (s_y - i) * x;
    917:       }
    918:       if (n11 >= 0) { /* right below */
    919:         x_t = lx[n11 % m];
    920:         y_t = ly[(n11 % (m * n)) / m];
    921:         /* z_t = z; */
    922:         s_t = bases[n11] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    923:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    924:       }
    925:     }

    927:     for (i = 0; i < y; i++) {
    928:       if (n12 >= 0) { /* directly left */
    929:         x_t = lx[n12 % m];
    930:         y_t = y;
    931:         /* z_t = z; */
    932:         s_t = bases[n12] + (i + 1) * x_t - s_x + k * x_t * y_t;
    933:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    934:       } else if (bx == DM_BOUNDARY_MIRROR) {
    935:         for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + s_x - j - 1 + k * x * y + i * x;
    936:       }

    938:       /* Interior */
    939:       s_t = bases[rank] + i * x + k * x * y;
    940:       for (j = 0; j < x; j++) idx[nn++] = s_t++;

    942:       if (n14 >= 0) { /* directly right */
    943:         x_t = lx[n14 % m];
    944:         y_t = y;
    945:         /* z_t = z; */
    946:         s_t = bases[n14] + i * x_t + k * x_t * y_t;
    947:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    948:       } else if (bx == DM_BOUNDARY_MIRROR) {
    949:         for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x - j - 1 + k * x * y + i * x;
    950:       }
    951:     }

    953:     for (i = 1; i <= s_y; i++) {
    954:       if (n15 >= 0) { /* left above */
    955:         x_t = lx[n15 % m];
    956:         y_t = ly[(n15 % (m * n)) / m];
    957:         /* z_t = z; */
    958:         s_t = bases[n15] + i * x_t - s_x + k * x_t * y_t;
    959:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    960:       }
    961:       if (n16 >= 0) { /* directly above */
    962:         x_t = x;
    963:         y_t = ly[(n16 % (m * n)) / m];
    964:         /* z_t = z; */
    965:         s_t = bases[n16] + (i - 1) * x_t + k * x_t * y_t;
    966:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    967:       } else if (by == DM_BOUNDARY_MIRROR) {
    968:         for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + k * x * y + (y - i) * x;
    969:       }
    970:       if (n17 >= 0) { /* right above */
    971:         x_t = lx[n17 % m];
    972:         y_t = ly[(n17 % (m * n)) / m];
    973:         /* z_t = z; */
    974:         s_t = bases[n17] + (i - 1) * x_t + k * x_t * y_t;
    975:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    976:       }
    977:     }
    978:   }

    980:   /* Upper Level */
    981:   for (k = 0; k < s_z; k++) {
    982:     for (i = 1; i <= s_y; i++) {
    983:       if (n18 >= 0) { /* left below */
    984:         x_t = lx[n18 % m];
    985:         y_t = ly[(n18 % (m * n)) / m];
    986:         /* z_t = lz[n18 / (m*n)]; */
    987:         s_t = bases[n18] - (s_y - i) * x_t - s_x + (k + 1) * x_t * y_t;
    988:         if (twod && (s_t >= M * N * P)) s_t = bases[n18] - (s_y - i) * x_t - s_x + x_t * y_t; /* 2d case */
    989:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    990:       }
    991:       if (n19 >= 0) { /* directly below */
    992:         x_t = x;
    993:         y_t = ly[(n19 % (m * n)) / m];
    994:         /* z_t = lz[n19 / (m*n)]; */
    995:         s_t = bases[n19] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    996:         if (twod && (s_t >= M * N * P)) s_t = bases[n19] - (s_y + 1 - i) * x_t + x_t * y_t; /* 2d case */
    997:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    998:       }
    999:       if (n20 >= 0) { /* right below */
    1000:         x_t = lx[n20 % m];
    1001:         y_t = ly[(n20 % (m * n)) / m];
    1002:         /* z_t = lz[n20 / (m*n)]; */
    1003:         s_t = bases[n20] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    1004:         if (twod && (s_t >= M * N * P)) s_t = bases[n20] - (s_y + 1 - i) * x_t + x_t * y_t; /* 2d case */
    1005:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1006:       }
    1007:     }

    1009:     for (i = 0; i < y; i++) {
    1010:       if (n21 >= 0) { /* directly left */
    1011:         x_t = lx[n21 % m];
    1012:         y_t = y;
    1013:         /* z_t = lz[n21 / (m*n)]; */
    1014:         s_t = bases[n21] + (i + 1) * x_t - s_x + k * x_t * y_t;
    1015:         if (twod && (s_t >= M * N * P)) s_t = bases[n21] + (i + 1) * x_t - s_x; /* 2d case */
    1016:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1017:       }

    1019:       if (n22 >= 0) { /* middle */
    1020:         x_t = x;
    1021:         y_t = y;
    1022:         /* z_t = lz[n22 / (m*n)]; */
    1023:         s_t = bases[n22] + i * x_t + k * x_t * y_t;
    1024:         if (twod && (s_t >= M * N * P)) s_t = bases[n22] + i * x_t; /* 2d case */
    1025:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1026:       } else if (bz == DM_BOUNDARY_MIRROR) {
    1027:         for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + (z - k - 1) * x * y + i * x;
    1028:       }

    1030:       if (n23 >= 0) { /* directly right */
    1031:         x_t = lx[n23 % m];
    1032:         y_t = y;
    1033:         /* z_t = lz[n23 / (m*n)]; */
    1034:         s_t = bases[n23] + i * x_t + k * x_t * y_t;
    1035:         if (twod && (s_t >= M * N * P)) s_t = bases[n23] + i * x_t; /* 2d case */
    1036:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1037:       }
    1038:     }

    1040:     for (i = 1; i <= s_y; i++) {
    1041:       if (n24 >= 0) { /* left above */
    1042:         x_t = lx[n24 % m];
    1043:         y_t = ly[(n24 % (m * n)) / m];
    1044:         /* z_t = lz[n24 / (m*n)]; */
    1045:         s_t = bases[n24] + i * x_t - s_x + k * x_t * y_t;
    1046:         if (twod && (s_t >= M * N * P)) s_t = bases[n24] + i * x_t - s_x; /* 2d case */
    1047:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1048:       }
    1049:       if (n25 >= 0) { /* directly above */
    1050:         x_t = x;
    1051:         y_t = ly[(n25 % (m * n)) / m];
    1052:         /* z_t = lz[n25 / (m*n)]; */
    1053:         s_t = bases[n25] + (i - 1) * x_t + k * x_t * y_t;
    1054:         if (twod && (s_t >= M * N * P)) s_t = bases[n25] + (i - 1) * x_t; /* 2d case */
    1055:         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1056:       }
    1057:       if (n26 >= 0) { /* right above */
    1058:         x_t = lx[n26 % m];
    1059:         y_t = ly[(n26 % (m * n)) / m];
    1060:         /* z_t = lz[n26 / (m*n)]; */
    1061:         s_t = bases[n26] + (i - 1) * x_t + k * x_t * y_t;
    1062:         if (twod && (s_t >= M * N * P)) s_t = bases[n26] + (i - 1) * x_t; /* 2d case */
    1063:         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1064:       }
    1065:     }
    1066:   }

    1068:   PetscCall(ISCreateBlock(comm, dof, nn, idx, PETSC_USE_POINTER, &from));
    1069:   PetscCall(VecScatterCreate(global, from, local, to, &gtol));
    1070:   PetscCall(ISDestroy(&to));
    1071:   PetscCall(ISDestroy(&from));

    1073:   if (stencil_type == DMDA_STENCIL_STAR) {
    1074:     n0  = sn0;
    1075:     n1  = sn1;
    1076:     n2  = sn2;
    1077:     n3  = sn3;
    1078:     n5  = sn5;
    1079:     n6  = sn6;
    1080:     n7  = sn7;
    1081:     n8  = sn8;
    1082:     n9  = sn9;
    1083:     n11 = sn11;
    1084:     n15 = sn15;
    1085:     n17 = sn17;
    1086:     n18 = sn18;
    1087:     n19 = sn19;
    1088:     n20 = sn20;
    1089:     n21 = sn21;
    1090:     n23 = sn23;
    1091:     n24 = sn24;
    1092:     n25 = sn25;
    1093:     n26 = sn26;
    1094:   }

    1096:   if ((stencil_type == DMDA_STENCIL_STAR) || (bx != DM_BOUNDARY_PERIODIC && bx) || (by != DM_BOUNDARY_PERIODIC && by) || (bz != DM_BOUNDARY_PERIODIC && bz)) {
    1097:     /*
    1098:         Recompute the local to global mappings, this time keeping the
    1099:       information about the cross corner processor numbers.
    1100:     */
    1101:     nn = 0;
    1102:     /* Bottom Level */
    1103:     for (k = 0; k < s_z; k++) {
    1104:       for (i = 1; i <= s_y; i++) {
    1105:         if (n0 >= 0) { /* left below */
    1106:           x_t = lx[n0 % m];
    1107:           y_t = ly[(n0 % (m * n)) / m];
    1108:           z_t = lz[n0 / (m * n)];
    1109:           s_t = bases[n0] + x_t * y_t * z_t - (s_y - i) * x_t - s_x - (s_z - k - 1) * x_t * y_t;
    1110:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1111:         } else if (Xs - xs < 0 && Ys - ys < 0 && Zs - zs < 0) {
    1112:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1113:         }
    1114:         if (n1 >= 0) { /* directly below */
    1115:           x_t = x;
    1116:           y_t = ly[(n1 % (m * n)) / m];
    1117:           z_t = lz[n1 / (m * n)];
    1118:           s_t = bases[n1] + x_t * y_t * z_t - (s_y + 1 - i) * x_t - (s_z - k - 1) * x_t * y_t;
    1119:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1120:         } else if (Ys - ys < 0 && Zs - zs < 0) {
    1121:           for (j = 0; j < x; j++) idx[nn++] = -1;
    1122:         }
    1123:         if (n2 >= 0) { /* right below */
    1124:           x_t = lx[n2 % m];
    1125:           y_t = ly[(n2 % (m * n)) / m];
    1126:           z_t = lz[n2 / (m * n)];
    1127:           s_t = bases[n2] + x_t * y_t * z_t - (s_y + 1 - i) * x_t - (s_z - k - 1) * x_t * y_t;
    1128:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1129:         } else if (xe - Xe < 0 && Ys - ys < 0 && Zs - zs < 0) {
    1130:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1131:         }
    1132:       }

    1134:       for (i = 0; i < y; i++) {
    1135:         if (n3 >= 0) { /* directly left */
    1136:           x_t = lx[n3 % m];
    1137:           y_t = y;
    1138:           z_t = lz[n3 / (m * n)];
    1139:           s_t = bases[n3] + (i + 1) * x_t - s_x + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1140:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1141:         } else if (Xs - xs < 0 && Zs - zs < 0) {
    1142:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1143:         }

    1145:         if (n4 >= 0) { /* middle */
    1146:           x_t = x;
    1147:           y_t = y;
    1148:           z_t = lz[n4 / (m * n)];
    1149:           s_t = bases[n4] + i * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1150:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1151:         } else if (Zs - zs < 0) {
    1152:           if (bz == DM_BOUNDARY_MIRROR) {
    1153:             for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + x * i + (s_z - k) * x * y;
    1154:           } else {
    1155:             for (j = 0; j < x; j++) idx[nn++] = -1;
    1156:           }
    1157:         }

    1159:         if (n5 >= 0) { /* directly right */
    1160:           x_t = lx[n5 % m];
    1161:           y_t = y;
    1162:           z_t = lz[n5 / (m * n)];
    1163:           s_t = bases[n5] + i * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1164:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1165:         } else if (xe - Xe < 0 && Zs - zs < 0) {
    1166:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1167:         }
    1168:       }

    1170:       for (i = 1; i <= s_y; i++) {
    1171:         if (n6 >= 0) { /* left above */
    1172:           x_t = lx[n6 % m];
    1173:           y_t = ly[(n6 % (m * n)) / m];
    1174:           z_t = lz[n6 / (m * n)];
    1175:           s_t = bases[n6] + i * x_t - s_x + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1176:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1177:         } else if (Xs - xs < 0 && ye - Ye < 0 && Zs - zs < 0) {
    1178:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1179:         }
    1180:         if (n7 >= 0) { /* directly above */
    1181:           x_t = x;
    1182:           y_t = ly[(n7 % (m * n)) / m];
    1183:           z_t = lz[n7 / (m * n)];
    1184:           s_t = bases[n7] + (i - 1) * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1185:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1186:         } else if (ye - Ye < 0 && Zs - zs < 0) {
    1187:           for (j = 0; j < x; j++) idx[nn++] = -1;
    1188:         }
    1189:         if (n8 >= 0) { /* right above */
    1190:           x_t = lx[n8 % m];
    1191:           y_t = ly[(n8 % (m * n)) / m];
    1192:           z_t = lz[n8 / (m * n)];
    1193:           s_t = bases[n8] + (i - 1) * x_t + x_t * y_t * z_t - (s_z - k) * x_t * y_t;
    1194:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1195:         } else if (xe - Xe < 0 && ye - Ye < 0 && Zs - zs < 0) {
    1196:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1197:         }
    1198:       }
    1199:     }

    1201:     /* Middle Level */
    1202:     for (k = 0; k < z; k++) {
    1203:       for (i = 1; i <= s_y; i++) {
    1204:         if (n9 >= 0) { /* left below */
    1205:           x_t = lx[n9 % m];
    1206:           y_t = ly[(n9 % (m * n)) / m];
    1207:           /* z_t = z; */
    1208:           s_t = bases[n9] - (s_y - i) * x_t - s_x + (k + 1) * x_t * y_t;
    1209:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1210:         } else if (Xs - xs < 0 && Ys - ys < 0) {
    1211:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1212:         }
    1213:         if (n10 >= 0) { /* directly below */
    1214:           x_t = x;
    1215:           y_t = ly[(n10 % (m * n)) / m];
    1216:           /* z_t = z; */
    1217:           s_t = bases[n10] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    1218:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1219:         } else if (Ys - ys < 0) {
    1220:           if (by == DM_BOUNDARY_MIRROR) {
    1221:             for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + k * x * y + (s_y - i + 1) * x;
    1222:           } else {
    1223:             for (j = 0; j < x; j++) idx[nn++] = -1;
    1224:           }
    1225:         }
    1226:         if (n11 >= 0) { /* right below */
    1227:           x_t = lx[n11 % m];
    1228:           y_t = ly[(n11 % (m * n)) / m];
    1229:           /* z_t = z; */
    1230:           s_t = bases[n11] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    1231:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1232:         } else if (xe - Xe < 0 && Ys - ys < 0) {
    1233:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1234:         }
    1235:       }

    1237:       for (i = 0; i < y; i++) {
    1238:         if (n12 >= 0) { /* directly left */
    1239:           x_t = lx[n12 % m];
    1240:           y_t = y;
    1241:           /* z_t = z; */
    1242:           s_t = bases[n12] + (i + 1) * x_t - s_x + k * x_t * y_t;
    1243:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1244:         } else if (Xs - xs < 0) {
    1245:           if (bx == DM_BOUNDARY_MIRROR) {
    1246:             for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + s_x - j - 1 + k * x * y + i * x + 1;
    1247:           } else {
    1248:             for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1249:           }
    1250:         }

    1252:         /* Interior */
    1253:         s_t = bases[rank] + i * x + k * x * y;
    1254:         for (j = 0; j < x; j++) idx[nn++] = s_t++;

    1256:         if (n14 >= 0) { /* directly right */
    1257:           x_t = lx[n14 % m];
    1258:           y_t = y;
    1259:           /* z_t = z; */
    1260:           s_t = bases[n14] + i * x_t + k * x_t * y_t;
    1261:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1262:         } else if (xe - Xe < 0) {
    1263:           if (bx == DM_BOUNDARY_MIRROR) {
    1264:             for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x - j - 1 + k * x * y + i * x - 1;
    1265:           } else {
    1266:             for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1267:           }
    1268:         }
    1269:       }

    1271:       for (i = 1; i <= s_y; i++) {
    1272:         if (n15 >= 0) { /* left above */
    1273:           x_t = lx[n15 % m];
    1274:           y_t = ly[(n15 % (m * n)) / m];
    1275:           /* z_t = z; */
    1276:           s_t = bases[n15] + i * x_t - s_x + k * x_t * y_t;
    1277:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1278:         } else if (Xs - xs < 0 && ye - Ye < 0) {
    1279:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1280:         }
    1281:         if (n16 >= 0) { /* directly above */
    1282:           x_t = x;
    1283:           y_t = ly[(n16 % (m * n)) / m];
    1284:           /* z_t = z; */
    1285:           s_t = bases[n16] + (i - 1) * x_t + k * x_t * y_t;
    1286:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1287:         } else if (ye - Ye < 0) {
    1288:           if (by == DM_BOUNDARY_MIRROR) {
    1289:             for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + k * x * y + (y - i - 1) * x;
    1290:           } else {
    1291:             for (j = 0; j < x; j++) idx[nn++] = -1;
    1292:           }
    1293:         }
    1294:         if (n17 >= 0) { /* right above */
    1295:           x_t = lx[n17 % m];
    1296:           y_t = ly[(n17 % (m * n)) / m];
    1297:           /* z_t = z; */
    1298:           s_t = bases[n17] + (i - 1) * x_t + k * x_t * y_t;
    1299:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1300:         } else if (xe - Xe < 0 && ye - Ye < 0) {
    1301:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1302:         }
    1303:       }
    1304:     }

    1306:     /* Upper Level */
    1307:     for (k = 0; k < s_z; k++) {
    1308:       for (i = 1; i <= s_y; i++) {
    1309:         if (n18 >= 0) { /* left below */
    1310:           x_t = lx[n18 % m];
    1311:           y_t = ly[(n18 % (m * n)) / m];
    1312:           /* z_t = lz[n18 / (m*n)]; */
    1313:           s_t = bases[n18] - (s_y - i) * x_t - s_x + (k + 1) * x_t * y_t;
    1314:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1315:         } else if (Xs - xs < 0 && Ys - ys < 0 && ze - Ze < 0) {
    1316:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1317:         }
    1318:         if (n19 >= 0) { /* directly below */
    1319:           x_t = x;
    1320:           y_t = ly[(n19 % (m * n)) / m];
    1321:           /* z_t = lz[n19 / (m*n)]; */
    1322:           s_t = bases[n19] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    1323:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1324:         } else if (Ys - ys < 0 && ze - Ze < 0) {
    1325:           for (j = 0; j < x; j++) idx[nn++] = -1;
    1326:         }
    1327:         if (n20 >= 0) { /* right below */
    1328:           x_t = lx[n20 % m];
    1329:           y_t = ly[(n20 % (m * n)) / m];
    1330:           /* z_t = lz[n20 / (m*n)]; */
    1331:           s_t = bases[n20] - (s_y + 1 - i) * x_t + (k + 1) * x_t * y_t;
    1332:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1333:         } else if (xe - Xe < 0 && Ys - ys < 0 && ze - Ze < 0) {
    1334:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1335:         }
    1336:       }

    1338:       for (i = 0; i < y; i++) {
    1339:         if (n21 >= 0) { /* directly left */
    1340:           x_t = lx[n21 % m];
    1341:           y_t = y;
    1342:           /* z_t = lz[n21 / (m*n)]; */
    1343:           s_t = bases[n21] + (i + 1) * x_t - s_x + k * x_t * y_t;
    1344:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1345:         } else if (Xs - xs < 0 && ze - Ze < 0) {
    1346:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1347:         }

    1349:         if (n22 >= 0) { /* middle */
    1350:           x_t = x;
    1351:           y_t = y;
    1352:           /* z_t = lz[n22 / (m*n)]; */
    1353:           s_t = bases[n22] + i * x_t + k * x_t * y_t;
    1354:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1355:         } else if (ze - Ze < 0) {
    1356:           if (bz == DM_BOUNDARY_MIRROR) {
    1357:             for (j = 0; j < x; j++) idx[nn++] = bases[rank] + j + (z - k - 2) * x * y + i * x;
    1358:           } else {
    1359:             for (j = 0; j < x; j++) idx[nn++] = -1;
    1360:           }
    1361:         }

    1363:         if (n23 >= 0) { /* directly right */
    1364:           x_t = lx[n23 % m];
    1365:           y_t = y;
    1366:           /* z_t = lz[n23 / (m*n)]; */
    1367:           s_t = bases[n23] + i * x_t + k * x_t * y_t;
    1368:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1369:         } else if (xe - Xe < 0 && ze - Ze < 0) {
    1370:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1371:         }
    1372:       }

    1374:       for (i = 1; i <= s_y; i++) {
    1375:         if (n24 >= 0) { /* left above */
    1376:           x_t = lx[n24 % m];
    1377:           y_t = ly[(n24 % (m * n)) / m];
    1378:           /* z_t = lz[n24 / (m*n)]; */
    1379:           s_t = bases[n24] + i * x_t - s_x + k * x_t * y_t;
    1380:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1381:         } else if (Xs - xs < 0 && ye - Ye < 0 && ze - Ze < 0) {
    1382:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1383:         }
    1384:         if (n25 >= 0) { /* directly above */
    1385:           x_t = x;
    1386:           y_t = ly[(n25 % (m * n)) / m];
    1387:           /* z_t = lz[n25 / (m*n)]; */
    1388:           s_t = bases[n25] + (i - 1) * x_t + k * x_t * y_t;
    1389:           for (j = 0; j < x_t; j++) idx[nn++] = s_t++;
    1390:         } else if (ye - Ye < 0 && ze - Ze < 0) {
    1391:           for (j = 0; j < x; j++) idx[nn++] = -1;
    1392:         }
    1393:         if (n26 >= 0) { /* right above */
    1394:           x_t = lx[n26 % m];
    1395:           y_t = ly[(n26 % (m * n)) / m];
    1396:           /* z_t = lz[n26 / (m*n)]; */
    1397:           s_t = bases[n26] + (i - 1) * x_t + k * x_t * y_t;
    1398:           for (j = 0; j < s_x; j++) idx[nn++] = s_t++;
    1399:         } else if (xe - Xe < 0 && ye - Ye < 0 && ze - Ze < 0) {
    1400:           for (j = 0; j < s_x; j++) idx[nn++] = -1;
    1401:         }
    1402:       }
    1403:     }
    1404:   }
    1405:   /*
    1406:      Set the local to global ordering in the global vector, this allows use
    1407:      of VecSetValuesLocal().
    1408:   */
    1409:   PetscCall(ISLocalToGlobalMappingCreate(comm, dof, nn, idx, PETSC_OWN_POINTER, &da->ltogmap));

    1411:   PetscCall(PetscFree2(bases, ldims));
    1412:   dd->m = m;
    1413:   dd->n = n;
    1414:   dd->p = p;
    1415:   /* note PETSc expects xs/xe/Xs/Xe to be multiplied by #dofs in many places */
    1416:   dd->xs = xs * dof;
    1417:   dd->xe = xe * dof;
    1418:   dd->ys = ys;
    1419:   dd->ye = ye;
    1420:   dd->zs = zs;
    1421:   dd->ze = ze;
    1422:   dd->Xs = Xs * dof;
    1423:   dd->Xe = Xe * dof;
    1424:   dd->Ys = Ys;
    1425:   dd->Ye = Ye;
    1426:   dd->Zs = Zs;
    1427:   dd->Ze = Ze;

    1429:   PetscCall(VecDestroy(&local));
    1430:   PetscCall(VecDestroy(&global));

    1432:   dd->gtol      = gtol;
    1433:   dd->base      = base;
    1434:   da->ops->view = DMView_DA_3d;
    1435:   dd->ltol      = NULL;
    1436:   dd->ao        = NULL;
    1437:   PetscFunctionReturn(PETSC_SUCCESS);
    1438: }

    1440: /*@
    1441:   DMDACreate3d - Creates an object that will manage the communication of three-dimensional
    1442:   regular array data that is distributed across one or more MPI processes.

    1444:   Collective

    1446:   Input Parameters:
    1447: + comm         - MPI communicator
    1448: . bx           - type of x ghost nodes the array have.
    1449:                  Use one of `DM_BOUNDARY_NONE`, `DM_BOUNDARY_GHOSTED`, `DM_BOUNDARY_PERIODIC`.
    1450: . by           - type of y ghost nodes the array have.
    1451:                  Use one of `DM_BOUNDARY_NONE`, `DM_BOUNDARY_GHOSTED`, `DM_BOUNDARY_PERIODIC`.
    1452: . bz           - type of z ghost nodes the array have.
    1453:                  Use one of `DM_BOUNDARY_NONE`, `DM_BOUNDARY_GHOSTED`, `DM_BOUNDARY_PERIODIC`.
    1454: . stencil_type - Type of stencil (`DMDA_STENCIL_STAR` or `DMDA_STENCIL_BOX`)
    1455: . M            - global dimension in the x direction of the array
    1456: . N            - global dimension in the y direction of the array
    1457: . P            - global dimension in the z direction of the array
    1458: . m            - corresponding number of processors in the x dimension (or `PETSC_DECIDE` to have calculated)
    1459: . n            - corresponding number of processors in the y dimension (or `PETSC_DECIDE` to have calculated)
    1460: . p            - corresponding number of processors in the z dimension (or `PETSC_DECIDE` to have calculated)
    1461: . dof          - number of degrees of freedom per node
    1462: . s            - stencil width
    1463: . lx           - arrays containing the number of nodes in each cell along the x  coordinates, or `NULL`.
    1464: . ly           - arrays containing the number of nodes in each cell along the y coordinates, or `NULL`.
    1465: - lz           - arrays containing the number of nodes in each cell along the z coordinates, or `NULL`.

    1467:   Output Parameter:
    1468: . da - the resulting distributed array object

    1470:   Options Database Keys:
    1471: + -dm_view            - Calls `DMView()` at the conclusion of `DMDACreate3d()`
    1472: . -da_grid_x nx       - number of grid points in the x direction
    1473: . -da_grid_y ny       - number of grid points in the y direction
    1474: . -da_grid_z nz       - number of grid points in the z direction
    1475: . -da_processors_x MX - number of processors in the x direction
    1476: . -da_processors_y MY - number of processors in the y direction
    1477: . -da_processors_z MZ - number of processors in the z direction
    1478: . -da_bd_x bx         - boundary type in the x direction
    1479: . -da_bd_y by         - boundary type in the y direction
    1480: . -da_bd_z bz         - boundary type in the z direction
    1481: . -da_bd_all bt       - boundary type in all directions
    1482: . -da_refine_x rx     - refinement ratio in the x direction
    1483: . -da_refine_y ry     - refinement ratio in the y direction
    1484: . -da_refine_z rz     - refinement ratio in the z direction
    1485: - -da_refine n        - refine the `DMDA` `n` times before creating it

    1487:   Level: beginner

    1489:   Notes:
    1490:   If `lx`, `ly`, or `lz` are non-null, these must be of length as `m`, `n`, `p` and the
    1491:   corresponding `m`, `n`, or `p` cannot be `PETSC_DECIDE`. Sum of the `lx` entries must be `M`,
    1492:   sum of the `ly` must `N`, sum of the `lz` must be `P`.

    1494:   The stencil type `DMDA_STENCIL_STAR` with width 1 corresponds to the
    1495:   standard 7-pt stencil, while `DMDA_STENCIL_BOX` with width 1 denotes
    1496:   the standard 27-pt stencil.

    1498:   The array data itself is NOT stored in the `DMDA`, it is stored in `Vec` objects;
    1499:   The appropriate vector objects can be obtained with calls to `DMCreateGlobalVector()`
    1500:   and `DMCreateLocalVector()` and calls to `VecDuplicate()` if more are needed.

    1502:   You must call `DMSetUp()` after this call before using this `DM`.

    1504:   To use the options database to change values in the `DMDA` call `DMSetFromOptions()` after this call
    1505:   but before `DMSetUp()`.

    1507: .seealso: [](sec_struct), `DM`, `DMDA`, `DMDestroy()`, `DMView()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMGlobalToLocalBegin()`, `DMDAGetRefinementFactor()`,
    1508:           `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToLocalBegin()`, `DMLocalToLocalEnd()`, `DMDASetRefinementFactor()`,
    1509:           `DMDAGetInfo()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`, `DMDACreateNaturalVector()`, `DMLoad()`, `DMDAGetOwnershipRanges()`,
    1510:           `DMStagCreate3d()`, `DMBoundaryType`
    1511: @*/
    1512: PetscErrorCode DMDACreate3d(MPI_Comm comm, DMBoundaryType bx, DMBoundaryType by, DMBoundaryType bz, DMDAStencilType stencil_type, PetscInt M, PetscInt N, PetscInt P, PetscInt m, PetscInt n, PetscInt p, PetscInt dof, PetscInt s, const PetscInt lx[], const PetscInt ly[], const PetscInt lz[], DM *da)
    1513: {
    1514:   PetscFunctionBegin;
    1515:   PetscCall(DMDACreate(comm, da));
    1516:   PetscCall(DMSetDimension(*da, 3));
    1517:   PetscCall(DMDASetSizes(*da, M, N, P));
    1518:   PetscCall(DMDASetNumProcs(*da, m, n, p));
    1519:   PetscCall(DMDASetBoundaryType(*da, bx, by, bz));
    1520:   PetscCall(DMDASetDof(*da, dof));
    1521:   PetscCall(DMDASetStencilType(*da, stencil_type));
    1522:   PetscCall(DMDASetStencilWidth(*da, s));
    1523:   PetscCall(DMDASetOwnershipRanges(*da, lx, ly, lz));
    1524:   PetscFunctionReturn(PETSC_SUCCESS);
    1525: }