LAPACK  3.10.0
LAPACK: Linear Algebra PACKage
cscal.f
Go to the documentation of this file.
1 *> \brief \b CSCAL
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 CSCAL(N,CA,CX,INCX)
12 *
13 * .. Scalar Arguments ..
14 * COMPLEX CA
15 * INTEGER INCX,N
16 * ..
17 * .. Array Arguments ..
18 * COMPLEX CX(*)
19 * ..
20 *
21 *
22 *> \par Purpose:
23 * =============
24 *>
25 *> \verbatim
26 *>
27 *> CSCAL 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] CA
40 *> \verbatim
41 *> CA is COMPLEX
42 *> On entry, CA specifies the scalar alpha.
43 *> \endverbatim
44 *>
45 *> \param[in,out] CX
46 *> \verbatim
47 *> CX is COMPLEX 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 CX
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 complex_blas_level1
65 *
66 *> \par Further Details:
67 * =====================
68 *>
69 *> \verbatim
70 *>
71 *> jack dongarra, linpack, 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 cscal(N,CA,CX,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 CA
85  INTEGER INCX,N
86 * ..
87 * .. Array Arguments ..
88  COMPLEX CX(*)
89 * ..
90 *
91 * =====================================================================
92 *
93 * .. Local Scalars ..
94  INTEGER I,NINCX
95 * ..
96  IF (n.LE.0 .OR. incx.LE.0) RETURN
97  IF (incx.EQ.1) THEN
98 *
99 * code for increment equal to 1
100 *
101  DO i = 1,n
102  cx(i) = ca*cx(i)
103  END DO
104  ELSE
105 *
106 * code for increment not equal to 1
107 *
108  nincx = n*incx
109  DO i = 1,nincx,incx
110  cx(i) = ca*cx(i)
111  END DO
112  END IF
113  RETURN
114 *
115 * End of CSCAL
116 *
117  END
subroutine cscal(N, CA, CX, INCX)
CSCAL
Definition: cscal.f:78