LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
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zdscal.f
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1*> \brief \b ZDSCAL
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 ZDSCAL(N,DA,ZX,INCX)
12*
13* .. Scalar Arguments ..
14* DOUBLE PRECISION DA
15* INTEGER INCX,N
16* ..
17* .. Array Arguments ..
18* COMPLEX*16 ZX(*)
19* ..
20*
21*
22*> \par Purpose:
23* =============
24*>
25*> \verbatim
26*>
27*> ZDSCAL 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] DA
40*> \verbatim
41*> DA is DOUBLE PRECISION
42*> On entry, DA 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 zdscal(N,DA,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 DOUBLE PRECISION DA
85 INTEGER INCX,N
86* ..
87* .. Array Arguments ..
88 COMPLEX*16 ZX(*)
89* ..
90*
91* =====================================================================
92*
93* .. Local Scalars ..
94 INTEGER I,NINCX
95* .. Parameters ..
96 DOUBLE PRECISION ONE
97 parameter(one=1.0d+0)
98* ..
99* .. Intrinsic Functions ..
100 INTRINSIC dble, dcmplx, dimag
101* ..
102 IF (n.LE.0 .OR. incx.LE.0 .OR. da.EQ.one) 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*dble(zx(i)),da*dimag(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*dble(zx(i)),da*dimag(zx(i)))
117 END DO
118 END IF
119 RETURN
120*
121* End of ZDSCAL
122*
123 END
subroutine zdscal(N, DA, ZX, INCX)
ZDSCAL
Definition: zdscal.f:78