LAPACK  3.11.0
LAPACK: Linear Algebra PACKage
zscal.f
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 * Arguments:
31 * ==========
32 *
33 *> \param[in] N
34 *> \verbatim
35 *> N is INTEGER
36 *> number of elements in input vector(s)
37 *> \endverbatim
38 *>
39 *> \param[in] ZA
40 *> \verbatim
41 *> ZA is COMPLEX*16
42 *> On entry, ZA specifies the scalar alpha.
43 *> \endverbatim
44 *>
45 *> \param[in,out] ZX
46 *> \verbatim
47 *> ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
48 *> \endverbatim
49 *>
50 *> \param[in] INCX
51 *> \verbatim
52 *> INCX is INTEGER
53 *> storage spacing between elements of ZX
54 *> \endverbatim
55 *
56 * Authors:
57 * ========
58 *
59 *> \author Univ. of Tennessee
60 *> \author Univ. of California Berkeley
61 *> \author Univ. of Colorado Denver
62 *> \author NAG Ltd.
63 *
64 *> \ingroup scal
65 *
66 *> \par Further Details:
67 * =====================
68 *>
69 *> \verbatim
70 *>
71 *> jack dongarra, 3/11/78.
72 *> modified 3/93 to return if incx .le. 0.
73 *> modified 12/3/93, array(1) declarations changed to array(*)
74 *> \endverbatim
75 *>
76 * =====================================================================
77  SUBROUTINE zscal(N,ZA,ZX,INCX)
78 *
79 * -- Reference BLAS level1 routine --
80 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
81 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
82 *
83 * .. Scalar Arguments ..
84  COMPLEX*16 ZA
85  INTEGER INCX,N
86 * ..
87 * .. Array Arguments ..
88  COMPLEX*16 ZX(*)
89 * ..
90 *
91 * =====================================================================
92 *
93 * .. Local Scalars ..
94  INTEGER I,NINCX
95 * ..
96 * .. Parameters ..
97  COMPLEX*16 ONE
98  parameter(one= (1.0d+0,0.0d+0))
99 * ..
100  IF (n.LE.0 .OR. incx.LE.0 .OR. za.EQ.one) RETURN
101  IF (incx.EQ.1) THEN
102 *
103 * code for increment equal to 1
104 *
105  DO i = 1,n
106  zx(i) = za*zx(i)
107  END DO
108  ELSE
109 *
110 * code for increment not equal to 1
111 *
112  nincx = n*incx
113  DO i = 1,nincx,incx
114  zx(i) = za*zx(i)
115  END DO
116  END IF
117  RETURN
118 *
119 * End of ZSCAL
120 *
121  END
zscal
subroutine zscal(N, ZA, ZX, INCX)
ZSCAL
Definition: zscal.f:78