LAPACK 3.11.0 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* 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 complex16_blas_level1
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
subroutine zscal(N, ZA, ZX, INCX)
ZSCAL
Definition: zscal.f:78