LAPACK  3.8.0
LAPACK: Linear Algebra PACKage

◆ 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.
Date
November 2017
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 80 of file zdscal.f.

80 *
81 * -- Reference BLAS level1 routine (version 3.8.0) --
82 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
83 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
84 * November 2017
85 *
86 * .. Scalar Arguments ..
87  DOUBLE PRECISION da
88  INTEGER incx,n
89 * ..
90 * .. Array Arguments ..
91  COMPLEX*16 zx(*)
92 * ..
93 *
94 * =====================================================================
95 *
96 * .. Local Scalars ..
97  INTEGER i,nincx
98 * ..
99 * .. Intrinsic Functions ..
100  INTRINSIC dcmplx
101 * ..
102  IF (n.LE.0 .OR. incx.LE.0) RETURN
103  IF (incx.EQ.1) THEN
104 *
105 * code for increment equal to 1
106 *
107  DO i = 1,n
108  zx(i) = dcmplx(da,0.0d0)*zx(i)
109  END DO
110  ELSE
111 *
112 * code for increment not equal to 1
113 *
114  nincx = n*incx
115  DO i = 1,nincx,incx
116  zx(i) = dcmplx(da,0.0d0)*zx(i)
117  END DO
118  END IF
119  RETURN