NAME

ssymm - perform one of the matrix-matrix operations   C := alpha∗A∗B + beta∗C or C := alpha∗B∗A + beta∗C

SYNOPSIS

SUBROUTINE SSYMM
( SIDE, UPLO, M, N, ALPHA, A, LDA, B, LDB, BETA, C, LDC )

void ssymm(char side, char uplo, long int m, long int n,
float alpha, float ∗sa, long int lda, float ∗sb, long int ldb, float sbeta,
 float ∗sc, long int ldc)

CHARACTER∗1 SIDE, UPLO

INTEGER M, N, LDA, LDB, LDC

REAL ALPHA, BETA

REAL A( LDA, ∗ ), B( LDB, ∗ ), C( LDC, ∗ )

PURPOSE

SSYMM  performs one of the matrix-matrix operations C := alpha∗A∗B + beta∗C or C := alpha∗B∗A + beta∗C where alpha and beta are scalars,  A is a symmetric matrix and  B and C are  m by n matrices. 
 

PARAMETERS

SIDE   - CHARACTER∗1. 
On entry,  SIDE  specifies whether  the  symmetric matrix  A appears on the  left or right  in the  operation as follows:
 
SIDE = ’L’ or ’l’   C := alpha∗A∗B + beta∗C,
 
SIDE = ’R’ or ’r’   C := alpha∗B∗A + beta∗C,
 
Unchanged on exit.

UPLO   - CHARACTER∗1. 
On  entry,   UPLO  specifies  whether  the  upper  or  lower triangular  part  of  the  symmetric  matrix   A  is  to  be referenced as follows:
 
UPLO = ’U’ or ’u’   Only the upper triangular part of the symmetric matrix is to be referenced.
 
UPLO = ’L’ or ’l’   Only the lower triangular part of the symmetric matrix is to be referenced.
 
Unchanged on exit.

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

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

ALPHA  - REAL. 
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.

A      - REAL array of DIMENSION ( LDA, ka ), where ka is
m  when  SIDE = ’L’ or ’l’  and is  n otherwise.
 
Before entry  with  SIDE = ’L’ or ’l’,  the  m by m  part of the array  A  must contain the  symmetric matrix,  such that when  UPLO = ’U’ or ’u’, the leading m by m upper triangular part of the array  A  must contain the upper triangular part of the  symmetric matrix and the  strictly  lower triangular part of  A  is not referenced,  and when  UPLO = ’L’ or ’l’, the leading  m by m  lower triangular part  of the  array  A must  contain  the  lower triangular part  of the  symmetric matrix and the  strictly upper triangular part of  A  is not referenced.
 
Before entry  with  SIDE = ’R’ or ’r’,  the  n by n  part of the array  A  must contain the  symmetric matrix,  such that when  UPLO = ’U’ or ’u’, the leading n by n upper triangular part of the array  A  must contain the upper triangular part of the  symmetric matrix and the  strictly  lower triangular part of  A  is not referenced,  and when  UPLO = ’L’ or ’l’, the leading  n by n  lower triangular part  of the  array  A must  contain  the  lower triangular part  of the  symmetric matrix and the  strictly upper triangular part of  A  is not referenced.
 
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 ), otherwise  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. Unchanged on exit.

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.

BETA   - REAL. 
On entry,  BETA  specifies the scalar  beta.  When  BETA  is supplied as zero then C need not be set on input. Unchanged on exit.

C      - REAL array of DIMENSION ( LDC, n ). 
Before entry, the leading  m by n  part of the array  C must contain the matrix  C,  except when  beta  is zero, in which case C need not be set on entry. On exit, the array  C  is overwritten by the  m by n updated matrix.

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

Sun, Inc.  —  Last change: 20 Sep 1996