# cgemv.f

          SUBROUTINE CGEMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y,
         $   INCY)
    C***BEGIN PROLOGUE  CGEMV
    C***PURPOSE  Multiply a complex vector by a complex general matrix.
    C***LIBRARY   SLATEC (BLAS)
    C***CATEGORY  D1B4
    C***TYPE      COMPLEX (SGEMV-S, DGEMV-D, CGEMV-C)
    C***KEYWORDS  LEVEL 2 BLAS, LINEAR ALGEBRA
    C***AUTHOR  Dongarra, J. J., (ANL)
    C           Du Croz, J., (NAG)
    C           Hammarling, S., (NAG)
    C           Hanson, R. J., (SNLA)
    C***DESCRIPTION
    C
    C  CGEMV  performs one of the matrix-vector operations
    C
    C     y := alpha*A*x + beta*y,   or   y := alpha*A'*x + beta*y,   or
    C
    C     y := alpha*conjg( A' )*x + beta*y,
    C
    C  where alpha and beta are scalars, x and y are vectors and A is an
    C  m by n matrix.
    C
    C  Parameters
    C  ==========
    C
    C  TRANS  - CHARACTER*1.
    C           On entry, TRANS specifies the operation to be performed as
    C           follows:
    C
    C              TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.
    C
    C              TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.
    C
    C              TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.
    C
    C           Unchanged on exit.
    C
    C  M      - INTEGER.
    C           On entry, M specifies the number of rows of the matrix A.
    C           M must be at least zero.
    C           Unchanged on exit.
    C
    C  N      - INTEGER.
    C           On entry, N specifies the number of columns of the matrix A.
    C           N must be at least zero.
    C           Unchanged on exit.
    C
    C  ALPHA  - COMPLEX         .
    C           On entry, ALPHA specifies the scalar alpha.
    C           Unchanged on exit.
    C
    C  A      - COMPLEX          array of DIMENSION ( LDA, n ).
    C           Before entry, the leading m by n part of the array A must
    C           contain the matrix of coefficients.
    C           Unchanged on exit.
    C
    C  LDA    - INTEGER.
    C           On entry, LDA specifies the first dimension of A as declared
    C           in the calling (sub) program. LDA must be at least
    C           max( 1, m ).
    C           Unchanged on exit.
    C
    C  X      - COMPLEX          array of DIMENSION at least
    C           ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
    C           and at least
    C           ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
    C           Before entry, the incremented array X must contain the
    C           vector x.
    C           Unchanged on exit.
    C
    C  INCX   - INTEGER.
    C           On entry, INCX specifies the increment for the elements of
    C           X. INCX must not be zero.
    C           Unchanged on exit.
    C
    C  BETA   - COMPLEX         .
    C           On entry, BETA specifies the scalar beta. When BETA is
    C           supplied as zero then Y need not be set on input.
    C           Unchanged on exit.
    C
    C  Y      - COMPLEX          array of DIMENSION at least
    C           ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
    C           and at least
    C           ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
    C           Before entry with BETA non-zero, the incremented array Y
    C           must contain the vector y. On exit, Y is overwritten by the
    C           updated vector y.
    C
    C  INCY   - INTEGER.
    C           On entry, INCY specifies the increment for the elements of
    C           Y. INCY must not be zero.
    C           Unchanged on exit.
    C
    C***REFERENCES  Dongarra, J. J., Du Croz, J., Hammarling, S., and
    C                 Hanson, R. J.  An extended set of Fortran basic linear
    C                 algebra subprograms.  ACM TOMS, Vol. 14, No. 1,
    C                 pp. 1-17, March 1988.
    C***ROUTINES CALLED  LSAME, XERBLA
    C***REVISION HISTORY  (YYMMDD)
    C   861022  DATE WRITTEN
    C   910605  Modified to meet SLATEC prologue standards.  Only comment
    C           lines were modified.  (BKS)
    C***END PROLOGUE  CGEMV