debian man page for zgemm

ZGEMM(3)							   BLAS routine 							  ZGEMM(3)

NAME
       ZGEMM - perform one of the matrix-matrix operations   C := alpha*op( A )*op( B ) + beta*C,

SYNOPSIS
       SUBROUTINE ZGEMM ( TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC )

	   CHARACTER*1	TRANSA, TRANSB

	   INTEGER	M, N, K, LDA, LDB, LDC

	   COMPLEX*16	ALPHA, BETA

	   COMPLEX*16	A( LDA, * ), B( LDB, * ), C( LDC, * )

PURPOSE
       ZGEMM  performs one of the matrix-matrix operations

       where  op( X ) is one of

	  op( X ) = X	or   op( X ) = X'   or	 op( X ) = conjg( X' ),

       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 - 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'.

       TRANSA = 'C' or 'c',  op( A ) = conjg( A' ).

       Unchanged on exit.

       TRANSB - 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'.

       TRANSB = 'C' or 'c',  op( B ) = conjg( B' ).

       Unchanged on exit.

       M      - 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.  Unchanged
	      on exit.

       N      - 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.  Unchanged on exit.

       K      - 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.  Unchanged on exit.

       ALPHA  - COMPLEX*16	.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       A      - COMPLEX*16	 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.	Unchanged on exit.

       LDA    - 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 ).  Unchanged on exit.

       B      - COMPLEX*16	 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.	Unchanged on exit.

       LDB    - 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 ).  Unchanged on exit.

       BETA   - COMPLEX*16	.
	      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*16	 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 ( alpha*op( A )*op( B ) + beta*C ).

       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.

BLAS routine							  16 October 1992							  ZGEMM(3)