dlavsp.f - Man Page

TESTING/LIN/dlavsp.f

Synopsis

Functions/Subroutines

subroutine dlavsp (uplo, trans, diag, n, nrhs, a, ipiv, b, ldb, info)
DLAVSP

Function/Subroutine Documentation

subroutine dlavsp (character uplo, character trans, character diag, integer n, integer nrhs, double precision, dimension( * ) a, integer, dimension( * ) ipiv, double precision, dimension( ldb, * ) b, integer ldb, integer info)

DLAVSP

Purpose:

 DLAVSP  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 DSPTRF.

 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' )
 If TRANS = 'C', 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
          = 'C':  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 DOUBLE PRECISION array, dimension (N*(N+1)/2)
          The block diagonal matrix D and the multipliers used to
          obtain the factor U or L, stored as a packed triangular
          matrix as computed by DSPTRF.

IPIV

          IPIV is INTEGER array, dimension (N)
          The pivot indices from DSPTRF.

B

          B is DOUBLE PRECISION 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 128 of file dlavsp.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page dlavsp(3) is an alias of dlavsp.f(3).

Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK