ZGEMV(1)

NAME
LAPACK-3 - performs one of the matrix-vector operations y := alpha*A*x + beta*y, or y := alpha*A**T*x + beta*y, or y := alpha*A**H*x + beta*y,

SYNOPSIS

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

DOUBLE
    COMPLEX ALPHA,BETA

INTEGER
    INCX,INCY,LDA,M,N

CHARACTER
    TRANS

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

PURPOSE
ZGEMV 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.

ARGUMENTS

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**T*x + beta*y.
     TRANS = 'C' or 'c' y := alpha*A**H*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*16      .
     On entry, ALPHA specifies the scalar alpha.
     Unchanged on exit.

A      - COMPLEX*16       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*16       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*16      .
     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*16       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.

FURTHER DETAILS
 Level 2 Blas routine.
 The vector and matrix arguments are not referenced when N = 0, or M = 0
 -- 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.