cgemv

CGEMV(l)                         BLAS routine                         CGEMV(l)



NAME
       CGEMV - perform one of the matrix-vector operations   y := alpha*A*x +
       beta*y, or y := alpha*A'*x + beta*y, or   y := alpha*conjg( A' )*x +
       beta*y,

SYNOPSIS
       SUBROUTINE CGEMV ( TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )

           COMPLEX      ALPHA, BETA

           INTEGER      INCX, INCY, LDA, M, N

           CHARACTER*1  TRANS

           COMPLEX      A( LDA, * ), X( * ), Y( * )

PURPOSE
       CGEMV  performs one of the matrix-vector operations

       where alpha and beta are scalars, x and y are vectors and A is an m by
       n matrix.


PARAMETERS
       TRANS  - CHARACTER*1.
              On entry, TRANS specifies the operation to be performed as
              follows:

              TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.

              TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.

              TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.

              Unchanged on exit.

       M      - INTEGER.
              On entry, M specifies the number of rows of the matrix A.  M
              must be at least zero.  Unchanged on exit.

       N      - INTEGER.
              On entry, N specifies the number of columns of the matrix A.  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, n ).
              Before entry, the leading m by n part of the array A must
              contain the matrix of coefficients.  Unchanged on exit.

       LDA    - INTEGER.
              On entry, LDA specifies the first dimension of A as declared in
              the calling (sub) program. LDA must be at least max( 1, m ).
              Unchanged on exit.

       X      - COMPLEX          array of DIMENSION at least
              ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n' and at
              least ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.  Before entry,
              the incremented array X must contain the vector x.  Unchanged on
              exit.

       INCX   - INTEGER.
              On entry, INCX specifies the increment for the elements of X.
              INCX must not be zero.  Unchanged on exit.

       BETA   - COMPLEX         .
              On entry, BETA specifies the scalar beta. When BETA is supplied
              as zero then Y need not be set on input.  Unchanged on exit.

       Y      - COMPLEX          array of DIMENSION at least
              ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at
              least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.  Before entry
              with BETA non-zero, the incremented array Y must contain the
              vector y. On exit, Y is overwritten by the updated vector y.

       INCY   - INTEGER.
              On entry, INCY specifies the increment for the elements of Y.
              INCY must not be zero.  Unchanged on exit.

              Level 2 Blas routine.

              -- Written on 22-October-1986.  Jack Dongarra, Argonne National
              Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag
              Central Office.  Richard Hanson, Sandia National Labs.



BLAS routine                    16 October 1992                       CGEMV(l)