ESMF_DGEMM Subroutine

subroutine ESMF_DGEMM(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)

\brief \b ESMF_DGEMM \par Purpose:

\verbatim

ESMF_DGEMM performs one of the matrix-matrix operations

C := alphaop( A )op( B ) + beta*C,

where op( X ) is one of

op( X ) = X or op( X ) = X**T,

alpha and beta are scalars, and A, B and C are matrices, with op( A ) an m by k matrix, op( B ) a k by n matrix and C an m by n matrix. \endverbatim \param[in] TRANSA \verbatim TRANSA is 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**T.

         TRANSA = 'C' or 'c',  op( A ) = A**T.

\endverbatim

\param[in] TRANSB \verbatim TRANSB is CHARACTER*1 On entry, TRANSB specifies the form of op( B ) to be used in the matrix multiplication as follows:

         TRANSB = 'N' or 'n',  op( B ) = B.

         TRANSB = 'T' or 't',  op( B ) = B**T.

         TRANSB = 'C' or 'c',  op( B ) = B**T.

\endverbatim

\param[in] M \verbatim M is INTEGER On entry, M specifies the number of rows of the matrix op( A ) and of the matrix C. M must be at least zero. \endverbatim

\param[in] N \verbatim N is INTEGER On entry, N specifies the number of columns of the matrix op( B ) and the number of columns of the matrix C. N must be at least zero. \endverbatim

\param[in] K \verbatim K is INTEGER On entry, K specifies the number of columns of the matrix op( A ) and the number of rows of the matrix op( B ). K must be at least zero. \endverbatim

\param[in] ALPHA \verbatim ALPHA is DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha. \endverbatim

\param[in] A \verbatim A is DOUBLE PRECISION array of DIMENSION ( LDA, ka ), where ka is k when TRANSA = ‘N’ or ‘n’, and is m otherwise. Before entry with TRANSA = ‘N’ or ‘n’, the leading m by k part of the array A must contain the matrix A, otherwise the leading k by m part of the array A must contain the matrix A. \endverbatim

\param[in] LDA \verbatim LDA is INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When TRANSA = ‘N’ or ‘n’ then LDA must be at least max( 1, m ), otherwise LDA must be at least max( 1, k ). \endverbatim

\param[in] B \verbatim B is DOUBLE PRECISION array of DIMENSION ( LDB, kb ), where kb is n when TRANSB = ‘N’ or ‘n’, and is k otherwise. Before entry with TRANSB = ‘N’ or ‘n’, the leading k by n part of the array B must contain the matrix B, otherwise the leading n by k part of the array B must contain the matrix B. \endverbatim

\param[in] LDB \verbatim LDB is INTEGER On entry, LDB specifies the first dimension of B as declared in the calling (sub) program. When TRANSB = ‘N’ or ‘n’ then LDB must be at least max( 1, k ), otherwise LDB must be at least max( 1, n ). \endverbatim

\param[in] BETA \verbatim BETA is DOUBLE PRECISION. On entry, BETA specifies the scalar beta. When BETA is supplied as zero then C need not be set on input. \endverbatim

\param[in,out] C \verbatim C is 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 matrix ( alphaop( A )op( B ) + beta*C ). \endverbatim

\param[in] LDC \verbatim LDC is 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 ). \endverbatim \author Univ. of Tennessee \author Univ. of California Berkeley \author Univ. of Colorado Denver \author NAG Ltd. \date November 2011 \ingroup double_blas_level3 \par Further Details:

\verbatim

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. \endverbatim

Arguments