chemm (l)  Linux Man Pages
chemm: performs one of the matrixmatrix operations C := alpha*A*B + beta*C,
NAME
CHEMM  performs one of the matrixmatrix operations C := alpha*A*B + beta*C,SYNOPSIS
 SUBROUTINE CHEMM(SIDE,UPLO,M,N,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
 COMPLEX ALPHA,BETA
 INTEGER LDA,LDB,LDC,M,N
 CHARACTER SIDE,UPLO
 COMPLEX A(LDA,*),B(LDB,*),C(LDC,*)
PURPOSE
CHEMM performs one of the matrixmatrix operations
or
C :=
where alpha and beta are scalars, A is an hermitian matrix and B and
C are m by n matrices.
ARGUMENTS
 SIDE  CHARACTER*1.

On entry, SIDE specifies whether the hermitian matrix A
appears on the left or right in the operation as follows:
SIDE = aqLaq or aqlaq C := alpha*A*B + beta*C,
SIDE = aqRaq or aqraq 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 hermitian matrix A is to be
referenced as follows:
UPLO = aqUaq or aquaq Only the upper triangular part of the hermitian matrix is to be referenced.
UPLO = aqLaq or aqlaq Only the lower triangular part of the hermitian 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  COMPLEX .
 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
 A  COMPLEX array of DIMENSION ( LDA, ka ), where ka is
 m when SIDE = aqLaq or aqlaq and is n otherwise. Before entry with SIDE = aqLaq or aqlaq, the m by m part of the array A must contain the hermitian matrix, such that when UPLO = aqUaq or aquaq, the leading m by m upper triangular part of the array A must contain the upper triangular part of the hermitian matrix and the strictly lower triangular part of A is not referenced, and when UPLO = aqLaq or aqlaq, the leading m by m lower triangular part of the array A must contain the lower triangular part of the hermitian matrix and the strictly upper triangular part of A is not referenced. Before entry with SIDE = aqRaq or aqraq, the n by n part of the array A must contain the hermitian matrix, such that when UPLO = aqUaq or aquaq, the leading n by n upper triangular part of the array A must contain the upper triangular part of the hermitian matrix and the strictly lower triangular part of A is not referenced, and when UPLO = aqLaq or aqlaq, the leading n by n lower triangular part of the array A must contain the lower triangular part of the hermitian matrix and the strictly upper triangular part of A is not referenced. Note that the imaginary parts of the diagonal elements need not be set, they are assumed to be zero. Unchanged on exit.
 LDA  INTEGER.
 On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When SIDE = aqLaq or aqlaq then LDA must be at least max( 1, m ), otherwise LDA must be at least max( 1, n ). Unchanged on exit.
 B  COMPLEX 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  COMPLEX .
 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  COMPLEX 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.
FURTHER DETAILS
Level 3 Blas routine.
 Written on 8February1989.
Jack Dongarra, Argonne National Laboratory.
Iain Duff, AERE Harwell.
Jeremy Du Croz, Numerical Algorithms Group Ltd.
Sven Hammarling, Numerical Algorithms Group Ltd.