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

Generated automatically by Doxygen for LAPACK from the source code.