Note: this is a BLAS routine and is not in libslatec.a
*DECK DGEMV
SUBROUTINE DGEMV (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y,
$ INCY)
C***BEGIN PROLOGUE DGEMV
C***PURPOSE Perform one of the matrix-vector operations.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1B4
C***TYPE DOUBLE PRECISION (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 DGEMV performs one of the matrix-vector operations
C
C y := alpha*A*x + beta*y, or y := alpha*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*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 - DOUBLE PRECISION.
C On entry, ALPHA specifies the scalar alpha.
C Unchanged on exit.
C
C A - DOUBLE PRECISION 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 - DOUBLE PRECISION 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 - DOUBLE PRECISION.
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 - DOUBLE PRECISION 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 DGEMV