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