TESTING/LIN/zlavsy.f(3)

NAME
TESTING/LIN/zlavsy.f

SYNOPSIS

  Functions/Subroutines
subroutine zlavsy (uplo, trans, diag, n, nrhs, a, lda, ipiv, b, ldb, info)
ZLAVSY

Function/Subroutine Documentation

  subroutine zlavsy (character uplo, character trans, character diag, integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex*16, dimension( ldb, * ) b, integer ldb, integer info)

ZLAVSY

Purpose:

    !>
    !> ZLAVSY performs one of the matrix-vector operations
    !>    x := A*x  or  x := A'*x,
    !> where x is an N element vector and  A is one of the factors
    !> from the block U*D*U' or L*D*L' factorization computed by ZSYTRF.
    !>
    !> If TRANS = 'N', multiplies by U  or U * D  (or L  or L * D)
    !> If TRANS = 'T', multiplies by U' or D * U' (or L' or D * L')
    !>

Parameters
    UPLO

    !>          UPLO is CHARACTER*1
    !>          Specifies whether the factor stored in A is upper or lower
    !>          triangular.
    !>          = 'U':  Upper triangular
    !>          = 'L':  Lower triangular
    !>

    TRANS

    !>          TRANS is CHARACTER*1
    !>          Specifies the operation to be performed:
    !>          = 'N':  x := A*x
    !>          = 'T':  x := A'*x
    !>

    DIAG

    !>          DIAG is CHARACTER*1
    !>          Specifies whether or not the diagonal blocks are unit
    !>          matrices.  If the diagonal blocks are assumed to be unit,
    !>          then A = U or A = L, otherwise A = U*D or A = L*D.
    !>          = 'U':  Diagonal blocks are assumed to be unit matrices.
    !>          = 'N':  Diagonal blocks are assumed to be non-unit matrices.
    !>

    N

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

    NRHS

    !>          NRHS is INTEGER
    !>          The number of right hand sides, i.e., the number of vectors
    !>          x to be multiplied by A.  NRHS >= 0.
    !>

    A

    !>          A is COMPLEX*16 array, dimension (LDA,N)
    !>          The block diagonal matrix D and the multipliers used to
    !>          obtain the factor U or L as computed by ZSYTRF.
    !>          Stored as a 2-D triangular matrix.
    !>

    LDA

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

    IPIV

    !>          IPIV is INTEGER array, dimension (N)
    !>          Details of the interchanges and the block structure of D,
    !>          as determined by ZSYTRF.
    !>
    !>          If UPLO = 'U':
    !>               If IPIV(k) > 0, then rows and columns k and IPIV(k)
    !>               were interchanged and D(k,k) is a 1-by-1 diagonal block.
    !>               (If IPIV( k ) = k, no interchange was done).
    !>
    !>               If IPIV(k) = IPIV(k-1) < 0, then rows and
    !>               columns k-1 and -IPIV(k) were interchanged,
    !>               D(k-1:k,k-1:k) is a 2-by-2 diagonal block.
    !>
    !>          If UPLO = 'L':
    !>               If IPIV(k) > 0, then rows and columns k and IPIV(k)
    !>               were interchanged and D(k,k) is a 1-by-1 diagonal block.
    !>               (If IPIV( k ) = k, no interchange was done).
    !>
    !>               If IPIV(k) = IPIV(k+1) < 0, then rows and
    !>               columns k+1 and -IPIV(k) were interchanged,
    !>               D(k:k+1,k:k+1) is a 2-by-2 diagonal block.
    !>

    B

    !>          B is COMPLEX*16 array, dimension (LDB,NRHS)
    !>          On entry, B contains NRHS vectors of length N.
    !>          On exit, B is overwritten with the product A * B.
    !>

    LDB

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

    INFO

    !>          INFO is INTEGER
    !>          = 0: successful exit
    !>          < 0: if INFO = -k, the k-th argument had an illegal value
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 151 of file zlavsy.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.