NAME

strmm - perform one of the matrix-matrix operations   B := alpha∗op( A )∗B, or B := alpha∗B∗op( A )

SYNOPSIS

SUBROUTINE STRMM
( SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB )

void strmm(char side, char uplo, char transa, char diag,
long int m, long int n, float alpha, float ∗sa, long int lda, float ∗sb, long int ldb)

CHARACTER∗1 SIDE, UPLO, TRANSA, DIAG

INTEGER M, N, LDA, LDB

REAL ALPHA

REAL A( LDA, ∗ ), B( LDB, ∗ )

PURPOSE

STRMM  performs one of the matrix-matrix operations B := alpha∗op( A )∗B, or B := alpha∗B∗op( A ) where  alpha  is a scalar,  B  is an m by n matrix,  A  is a unit, or non-unit,  upper or lower triangular matrix  and  op( A )  is one  of
 
   op( A ) = A   or   op( A ) = A’.
 

PARAMETERS

SIDE   - CHARACTER∗1. 
On entry,  SIDE specifies whether  op( A ) multiplies B from the left or right as follows:
 
SIDE = ’L’ or ’l’   B := alpha∗op( A )∗B.
 
SIDE = ’R’ or ’r’   B := alpha∗B∗op( A ).
 
Unchanged on exit.

UPLO   - CHARACTER∗1. 
On entry, UPLO specifies whether the matrix A is an upper or lower triangular matrix as follows:
 
UPLO = ’U’ or ’u’   A is an upper triangular matrix.
 
UPLO = ’L’ or ’l’   A is a lower triangular matrix.
 
Unchanged on exit.
 
TRANSA - CHARACTER∗1. On entry, TRANSA specifies the form of op( A ) to be used in the matrix multiplication as follows:
 
TRANSA = ’N’ or ’n’   op( A ) = A.
 
TRANSA = ’T’ or ’t’   op( A ) = A’.
 
TRANSA = ’C’ or ’c’   op( A ) = A’.
 
Unchanged on exit.

DIAG   - CHARACTER∗1. 
On entry, DIAG specifies whether or not A is unit triangular as follows:
 
DIAG = ’U’ or ’u’   A is assumed to be unit triangular.
 
DIAG = ’N’ or ’n’   A is not assumed to be unit triangular.
 
Unchanged on exit.

M      - INTEGER. 
On entry, M specifies the number of rows of B. M must be at least zero. Unchanged on exit.

N      - INTEGER. 
On entry, N specifies the number of columns of B.  N must be at least zero. Unchanged on exit.

ALPHA  - REAL. 
On entry,  ALPHA specifies the scalar  alpha. When  alpha is zero then  A is not referenced and  B need not be set before entry. Unchanged on exit.

A      - REAL array of DIMENSION ( LDA, k ), where k is m
when  SIDE = ’L’ or ’l’  and is  n  when  SIDE = ’R’ or ’r’.
 
Before entry  with  UPLO = ’U’ or ’u’,  the  leading  k by k upper triangular part of the array  A must contain the upper triangular matrix  and the strictly lower triangular part of A is not referenced.
 
Before entry  with  UPLO = ’L’ or ’l’,  the  leading  k by k lower triangular part of the array  A must contain the lower triangular matrix  and the strictly upper triangular part of A is not referenced.
 
Note that when  DIAG = ’U’ or ’u’,  the diagonal elements of A  are not referenced either,  but are assumed to be  unity. Unchanged on exit.

LDA    - INTEGER. 
On entry, LDA specifies the first dimension of A as declared in the calling (sub) program.  When  SIDE = ’L’ or ’l’  then LDA  must be at least  max( 1, m ),  when  SIDE = ’R’ or ’r’ then LDA must be at least max( 1, n ). Unchanged on exit.

B      - REAL array of DIMENSION ( LDB, n ). 
Before entry,  the leading  m by n part of the array  B must contain the matrix  B,  and  on exit  is overwritten  by the transformed matrix.

LDB    - INTEGER. 
On entry, LDB specifies the first dimension of B as declared in  the  calling  (sub)  program.   LDB  must  be  at  least max( 1, m ). Unchanged on exit.

Sun, Inc.  —  Last change: 20 Sep 1996