TESTING/LIN/dsyt01_3.f(3)

NAME
TESTING/LIN/dsyt01_3.f

SYNOPSIS

  Functions/Subroutines
subroutine dsyt01_3 (uplo, n, a, lda, afac, ldafac, e, ipiv, c, ldc, rwork, resid)
DSYT01_3

Function/Subroutine Documentation

  subroutine dsyt01_3 (character uplo, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldafac, * ) afac, integer ldafac, double precision, dimension( * ) e, integer, dimension( * ) ipiv, double precision, dimension( ldc, * ) c, integer ldc, double precision, dimension( * ) rwork, double precision resid)

DSYT01_3

Purpose:

    !>
    !> DSYT01_3 reconstructs a symmetric indefinite matrix A from its
    !> block L*D*L' or U*D*U' factorization computed by DSYTRF_RK
    !> (or DSYTRF_BK) and computes the residual
    !>    norm( C - A ) / ( N * norm(A) * EPS ),
    !> where C is the reconstructed matrix and EPS is the machine epsilon.
    !>

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.
    !>

    A

    !>          A is DOUBLE PRECISION array, dimension (LDA,N)
    !>          The original symmetric matrix A.
    !>

    LDA

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

    AFAC

    !>          AFAC is DOUBLE PRECISION array, dimension (LDAFAC,N)
    !>          Diagonal of the block diagonal matrix D and factors U or L
    !>          as computed by DSYTRF_RK and DSYTRF_BK:
    !>            a) ONLY diagonal elements of the symmetric block diagonal
    !>               matrix D on the diagonal of A, i.e. D(k,k) = A(k,k);
    !>               (superdiagonal (or subdiagonal) elements of D
    !>                should be provided on entry in array E), and
    !>            b) If UPLO = 'U': factor U in the superdiagonal part of A.
    !>               If UPLO = 'L': factor L in the subdiagonal part of A.
    !>

    LDAFAC

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

    E

    !>          E is DOUBLE PRECISION array, dimension (N)
    !>          On entry, contains the superdiagonal (or subdiagonal)
    !>          elements of the symmetric block diagonal matrix D
    !>          with 1-by-1 or 2-by-2 diagonal blocks, where
    !>          If UPLO = 'U': E(i) = D(i-1,i),i=2:N, E(1) not referenced;
    !>          If UPLO = 'L': E(i) = D(i+1,i),i=1:N-1, E(N) not referenced.
    !>

    IPIV

    !>          IPIV is INTEGER array, dimension (N)
    !>          The pivot indices from DSYTRF_RK (or DSYTRF_BK).
    !>

    C

    !>          C is DOUBLE PRECISION array, dimension (LDC,N)
    !>

    LDC

    !>          LDC is INTEGER
    !>          The leading dimension of the array C.  LDC >= max(1,N).
    !>

    RWORK

    !>          RWORK is DOUBLE PRECISION array, dimension (N)
    !>

    RESID

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

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 138 of file dsyt01_3.f.

Author

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