BLAS/SRC/dgemm.f(3)

NAME
BLAS/SRC/dgemm.f

SYNOPSIS

  Functions/Subroutines
subroutine dgemm (transa, transb, m, n, k, alpha, a, lda, b, ldb, beta, c, ldc)
DGEMM

Function/Subroutine Documentation

  subroutine dgemm (character transa, character transb, integer m, integer n, integer k, double precision alpha, double precision, dimension(lda,*) a, integer lda, double precision, dimension(ldb,*) b, integer ldb, double precision beta, double precision, dimension(ldc,*) c, integer ldc)

DGEMM

Purpose:

    !>
    !> DGEMM  performs one of the matrix-matrix operations
    !>
    !>    C := alpha*op( 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.
    !>

Parameters
    TRANSA

    !>          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.
    !>

    TRANSB

    !>          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.
    !>

    M

    !>          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.
    !>

    N

    !>          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.
    !>

    K

    !>          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.
    !>

    ALPHA

    !>          ALPHA is DOUBLE PRECISION.
    !>           On entry, ALPHA specifies the scalar alpha.
    !>

    A

    !>          A is DOUBLE PRECISION array, 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.
    !>

    LDA

    !>          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 ).
    !>

    B

    !>          B is DOUBLE PRECISION array, 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.
    !>

    LDB

    !>          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 ).
    !>

    BETA

    !>          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.
    !>

    C

    !>          C is DOUBLE PRECISION array, 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
    !>           ( alpha*op( A )*op( B ) + beta*C ).
    !>

    LDC

    !>          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 ).
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Further Details:

    !>
    !>  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.
    !>

Definition at line 186 of file dgemm.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.