LAPACK  3.5.0
LAPACK: Linear Algebra PACKage
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zscal.f
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1 *> \brief \b ZSCAL
2 *
3 * =========== DOCUMENTATION ===========
4 *
5 * Online html documentation available at
6 * http://www.netlib.org/lapack/explore-html/
7 *
8 * Definition:
9 * ===========
10 *
11 * SUBROUTINE ZSCAL(N,ZA,ZX,INCX)
12 *
13 * .. Scalar Arguments ..
14 * COMPLEX*16 ZA
15 * INTEGER INCX,N
16 * ..
17 * .. Array Arguments ..
18 * COMPLEX*16 ZX(*)
19 * ..
20 *
21 *
22 *> \par Purpose:
23 * =============
24 *>
25 *> \verbatim
26 *>
27 *> ZSCAL scales a vector by a constant.
28 *> \endverbatim
29 *
30 * Authors:
31 * ========
32 *
33 *> \author Univ. of Tennessee
34 *> \author Univ. of California Berkeley
35 *> \author Univ. of Colorado Denver
36 *> \author NAG Ltd.
37 *
38 *> \date November 2011
39 *
40 *> \ingroup complex16_blas_level1
41 *
42 *> \par Further Details:
43 * =====================
44 *>
45 *> \verbatim
46 *>
47 *> jack dongarra, 3/11/78.
48 *> modified 3/93 to return if incx .le. 0.
49 *> modified 12/3/93, array(1) declarations changed to array(*)
50 *> \endverbatim
51 *>
52 * =====================================================================
53  SUBROUTINE zscal(N,ZA,ZX,INCX)
54 *
55 * -- Reference BLAS level1 routine (version 3.4.0) --
56 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
57 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
58 * November 2011
59 *
60 * .. Scalar Arguments ..
61  COMPLEX*16 za
62  INTEGER incx,n
63 * ..
64 * .. Array Arguments ..
65  COMPLEX*16 zx(*)
66 * ..
67 *
68 * =====================================================================
69 *
70 * .. Local Scalars ..
71  INTEGER i,nincx
72 * ..
73  IF (n.LE.0 .OR. incx.LE.0) RETURN
74  IF (incx.EQ.1) THEN
75 *
76 * code for increment equal to 1
77 *
78  DO i = 1,n
79  zx(i) = za*zx(i)
80  END DO
81  ELSE
82 *
83 * code for increment not equal to 1
84 *
85  nincx = n*incx
86  DO i = 1,nincx,incx
87  zx(i) = za*zx(i)
88  END DO
89  END IF
90  RETURN
91  END