zdscal()

subroutine zdscal	(	integer	n,
		double precision	da,
		complex*16, dimension(*)	zx,
		integer	incx
	)

ZDSCAL

Purpose:

    ZDSCAL scales a vector by a constant.

Parameters

[in]	N	N is INTEGER number of elements in input vector(s)
[in]	DA	DA is DOUBLE PRECISION On entry, DA specifies the scalar alpha.
[in,out]	ZX	ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]	INCX	INCX is INTEGER storage spacing between elements of ZX

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Further Details:

     jack dongarra, 3/11/78.
     modified 3/93 to return if incx .le. 0.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 77 of file zdscal.f.

*
*  -- Reference BLAS level1 routine --
*  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      DOUBLE PRECISION DA
      INTEGER INCX,N
*     ..
*     .. Array Arguments ..
      COMPLEX*16 ZX(*)
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER I,NINCX
*     .. Parameters ..
      DOUBLE PRECISION ONE
      parameter(one=1.0d+0)
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC dble, dcmplx, dimag
*     ..
      IF (n.LE.0 .OR. incx.LE.0 .OR. da.EQ.one) RETURN
      IF (incx.EQ.1) THEN
*
*        code for increment equal to 1
*
         DO i = 1,n
            zx(i) = dcmplx(da*dble(zx(i)),da*dimag(zx(i)))
         END DO
      ELSE
*
*        code for increment not equal to 1
*
         nincx = n*incx
         DO i = 1,nincx,incx
            zx(i) = dcmplx(da*dble(zx(i)),da*dimag(zx(i)))
         END DO
      END IF
      RETURN
*
*     End of ZDSCAL
*