slagtm.f man page

slagtm.f —

Synopsis

Functions/Subroutines

subroutine slagtm (TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB)
SLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

Function/Subroutine Documentation

subroutine slagtm (characterTRANS, integerN, integerNRHS, realALPHA, real, dimension( * )DL, real, dimension( * )D, real, dimension( * )DU, real, dimension( ldx, * )X, integerLDX, realBETA, real, dimension( ldb, * )B, integerLDB)

SLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

Purpose:

SLAGTM performs a matrix-vector product of the form

   B := alpha * A * X + beta * B

where A is a tridiagonal matrix of order N, B and X are N by NRHS
matrices, and alpha and beta are real scalars, each of which may be
0., 1., or -1.

Parameters:

TRANS

TRANS is CHARACTER*1
Specifies the operation applied to A.
= 'N':  No transpose, B := alpha * A * X + beta * B
= 'T':  Transpose,    B := alpha * A'* X + beta * B
= 'C':  Conjugate transpose = Transpose

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 0., 1., or -1.; otherwise,
it is assumed to be 0.

DL

DL is REAL array, dimension (N-1)
The (n-1) sub-diagonal elements of T.

D

D is REAL array, dimension (N)
The diagonal elements of T.

DU

DU is REAL array, dimension (N-1)
The (n-1) super-diagonal elements of T.

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.

Date:

September 2012

Definition at line 145 of file slagtm.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

slagtm(3) is an alias of slagtm.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK