TESTING/LIN/dpbt01.f(3)

NAME
TESTING/LIN/dpbt01.f

SYNOPSIS

  Functions/Subroutines
subroutine dpbt01 (uplo, n, kd, a, lda, afac, ldafac, rwork, resid)
DPBT01

Function/Subroutine Documentation

  subroutine dpbt01 (character uplo, integer n, integer kd, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldafac, * ) afac, integer ldafac, double precision, dimension( * ) rwork, double precision resid)

DPBT01

Purpose:

     DPBT01 reconstructs a symmetric positive definite band matrix A from
     its L*L' or U'*U factorization and computes the residual
        norm( L*L' - A ) / ( N * norm(A) * EPS ) or
        norm( U'*U - A ) / ( N * norm(A) * EPS ),
     where EPS is the machine epsilon, L' is the conjugate transpose of
     L, and U' is the conjugate transpose of U.

Parameters
    UPLO

              UPLO is CHARACTER*1
              Specifies whether the upper or lower triangular part of the
              symmetric matrix A is stored:
              = 'U':  Upper triangular
              = 'L':  Lower triangular

    N

              N is INTEGER
              The number of rows and columns of the matrix A.  N >= 0.

    KD

              KD is INTEGER
              The number of super-diagonals of the matrix A if UPLO = 'U',
              or the number of sub-diagonals if UPLO = 'L'.  KD >= 0.

    A

              A is DOUBLE PRECISION array, dimension (LDA,N)
              The original symmetric band matrix A.  If UPLO = 'U', the
              upper triangular part of A is stored as a band matrix; if
              UPLO = 'L', the lower triangular part of A is stored.  The
              columns of the appropriate triangle are stored in the columns
              of A and the diagonals of the triangle are stored in the rows
              of A.  See DPBTRF for further details.

    LDA

              LDA is INTEGER.
              The leading dimension of the array A.  LDA >= max(1,KD+1).

    AFAC

              AFAC is DOUBLE PRECISION array, dimension (LDAFAC,N)
              The factored form of the matrix A.  AFAC contains the factor
              L or U from the L*L' or U'*U factorization in band storage
              format, as computed by DPBTRF.

    LDAFAC

              LDAFAC is INTEGER
              The leading dimension of the array AFAC.
              LDAFAC >= max(1,KD+1).

    RWORK

              RWORK is DOUBLE PRECISION array, dimension (N)

    RESID

              RESID is DOUBLE PRECISION
              If UPLO = 'L', norm(L*L' - A) / ( N * norm(A) * EPS )
              If UPLO = 'U', norm(U'*U - A) / ( N * norm(A) * EPS )

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 117 of file dpbt01.f.

Author

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