slaptm.f3
Usage
Functions/Subroutines
subroutine slaptm (n, nrhs, alpha, d, e, x, ldx, beta, b, ldb)
SLAPTM
Function/Subroutine Documentation
subroutine slaptm (integer n, integer nrhs, real alpha, real, dimension( * ) d, real, dimension( * ) e, real, dimension( ldx, * ) x, integer ldx, real beta, real, dimension( ldb, * ) b, integer ldb)
SLAPTM
Purpose:
!> !> SLAPTM multiplies an N by NRHS matrix X by a symmetric tridiagonal !> matrix A and stores the result in a matrix B. The operation has the !> form !> !> B := alpha * A * X + beta * B !> !> where alpha may be either 1. or -1. and beta may be 0., 1., or -1. !>
Parameters
N
!> N is INTEGER !> The order of the matrix A. N >= 0. !>
NRHS
!> NRHS is INTEGER !> The number of right hand sides, i.e., the number of columns !> of the matrices X and B. !>
ALPHA
!> ALPHA is REAL !> The scalar alpha. ALPHA must be 1. or -1.; otherwise, !> it is assumed to be 0. !>
D
!> D is REAL array, dimension (N) !> The n diagonal elements of the tridiagonal matrix A. !>
E
!> E is REAL array, dimension (N-1) !> The (n-1) subdiagonal or superdiagonal elements of A. !>
X
!> X is REAL array, dimension (LDX,NRHS) !> The N by NRHS matrix X. !>
LDX
!> LDX is INTEGER !> The leading dimension of the array X. LDX >= max(N,1). !>
BETA
!> BETA is REAL !> The scalar beta. BETA must be 0., 1., or -1.; otherwise, !> it is assumed to be 1. !>
B
!> B is REAL array, dimension (LDB,NRHS) !> On entry, the N by NRHS matrix B. !> On exit, B is overwritten by the matrix expression !> B := alpha * A * X + beta * B. !>
LDB
!> LDB is INTEGER !> The leading dimension of the array B. LDB >= max(N,1). !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 115 of file slaptm.f.