.TH DSYMM 1 "November 2006" "BLAS routine" "BLAS routine" .SH NAME DSYMM - one of the matrix-matrix operations C := alpha*A*B + beta*C, .SH SYNOPSIS .TP 61 SUBROUTINE DSYMM(SIDE,UPLO,M,N,ALPHA,A,LDA,B,LDB,BETA,C,LDC) .TP 61 .ti +4 DOUBLE PRECISION ALPHA,BETA .TP 61 .ti +4 INTEGER LDA,LDB,LDC,M,N .TP 61 .ti +4 CHARACTER SIDE,UPLO .TP 61 .ti +4 DOUBLE PRECISION A(LDA,*),B(LDB,*),C(LDC,*) .SH PURPOSE DSYMM performs one of the matrix-matrix operations or .br C := alpha*B*A + beta*C, .br where alpha and beta are scalars, A is a symmetric matrix and B and C are m by n matrices. .br .SH ARGUMENTS .TP 7 SIDE - CHARACTER*1. On entry, SIDE specifies whether the symmetric matrix A appears on the left or right in the operation as follows: SIDE = \(aqL\(aq or \(aql\(aq C := alpha*A*B + beta*C, SIDE = \(aqR\(aq or \(aqr\(aq C := alpha*B*A + beta*C, Unchanged on exit. .TP 7 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 = \(aqU\(aq or \(aqu\(aq Only the upper triangular part of the symmetric matrix is to be referenced. UPLO = \(aqL\(aq or \(aql\(aq Only the lower triangular part of the symmetric matrix is to be referenced. Unchanged on exit. .TP 7 M - INTEGER. On entry, M specifies the number of rows of the matrix C. M must be at least zero. Unchanged on exit. .TP 7 N - INTEGER. On entry, N specifies the number of columns of the matrix C. N must be at least zero. Unchanged on exit. .TP 7 ALPHA - DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha. Unchanged on exit. .TP 7 A - DOUBLE PRECISION array of DIMENSION ( LDA, ka ), where ka is m when SIDE = \(aqL\(aq or \(aql\(aq and is n otherwise. Before entry with SIDE = \(aqL\(aq or \(aql\(aq, the m by m part of the array A must contain the symmetric matrix, such that when UPLO = \(aqU\(aq or \(aqu\(aq, 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 = \(aqL\(aq or \(aql\(aq, 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 = \(aqR\(aq or \(aqr\(aq, the n by n part of the array A must contain the symmetric matrix, such that when UPLO = \(aqU\(aq or \(aqu\(aq, 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 = \(aqL\(aq or \(aql\(aq, 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. .TP 7 LDA - INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When SIDE = \(aqL\(aq or \(aql\(aq then LDA must be at least max( 1, m ), otherwise LDA must be at least max( 1, n ). Unchanged on exit. .TP 7 B - DOUBLE PRECISION 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. .TP 7 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. .TP 7 BETA - DOUBLE PRECISION. On entry, BETA specifies the scalar beta. When BETA is supplied as zero then C need not be set on input. Unchanged on exit. .TP 7 C - DOUBLE PRECISION 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. .TP 7 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. Level 3 Blas routine. -- Written on 8-February-1989. Jack Dongarra, Argonne National Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms Group Ltd. .. External Functions .. .. .. External Subroutines .. ..