LAPACK  3.4.2
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zlartv.f
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1 *> \brief \b ZLARTV applies a vector of plane rotations with real cosines and complex sines to the elements of a pair of vectors.
2 *
3 * =========== DOCUMENTATION ===========
4 *
5 * Online html documentation available at
6 * http://www.netlib.org/lapack/explore-html/
7 *
8 *> \htmlonly
9 *> Download ZLARTV + dependencies
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11 *> [TGZ]</a>
12 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zlartv.f">
13 *> [ZIP]</a>
14 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlartv.f">
15 *> [TXT]</a>
16 *> \endhtmlonly
17 *
18 * Definition:
19 * ===========
20 *
21 * SUBROUTINE ZLARTV( N, X, INCX, Y, INCY, C, S, INCC )
22 *
23 * .. Scalar Arguments ..
24 * INTEGER INCC, INCX, INCY, N
25 * ..
26 * .. Array Arguments ..
27 * DOUBLE PRECISION C( * )
28 * COMPLEX*16 S( * ), X( * ), Y( * )
29 * ..
30 *
31 *
32 *> \par Purpose:
33 * =============
34 *>
35 *> \verbatim
36 *>
37 *> ZLARTV applies a vector of complex plane rotations with real cosines
38 *> to elements of the complex vectors x and y. For i = 1,2,...,n
39 *>
40 *> ( x(i) ) := ( c(i) s(i) ) ( x(i) )
41 *> ( y(i) ) ( -conjg(s(i)) c(i) ) ( y(i) )
42 *> \endverbatim
43 *
44 * Arguments:
45 * ==========
46 *
47 *> \param[in] N
48 *> \verbatim
49 *> N is INTEGER
50 *> The number of plane rotations to be applied.
51 *> \endverbatim
52 *>
53 *> \param[in,out] X
54 *> \verbatim
55 *> X is COMPLEX*16 array, dimension (1+(N-1)*INCX)
56 *> The vector x.
57 *> \endverbatim
58 *>
59 *> \param[in] INCX
60 *> \verbatim
61 *> INCX is INTEGER
62 *> The increment between elements of X. INCX > 0.
63 *> \endverbatim
64 *>
65 *> \param[in,out] Y
66 *> \verbatim
67 *> Y is COMPLEX*16 array, dimension (1+(N-1)*INCY)
68 *> The vector y.
69 *> \endverbatim
70 *>
71 *> \param[in] INCY
72 *> \verbatim
73 *> INCY is INTEGER
74 *> The increment between elements of Y. INCY > 0.
75 *> \endverbatim
76 *>
77 *> \param[in] C
78 *> \verbatim
79 *> C is DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
80 *> The cosines of the plane rotations.
81 *> \endverbatim
82 *>
83 *> \param[in] S
84 *> \verbatim
85 *> S is COMPLEX*16 array, dimension (1+(N-1)*INCC)
86 *> The sines of the plane rotations.
87 *> \endverbatim
88 *>
89 *> \param[in] INCC
90 *> \verbatim
91 *> INCC is INTEGER
92 *> The increment between elements of C and S. INCC > 0.
93 *> \endverbatim
94 *
95 * Authors:
96 * ========
97 *
98 *> \author Univ. of Tennessee
99 *> \author Univ. of California Berkeley
100 *> \author Univ. of Colorado Denver
101 *> \author NAG Ltd.
102 *
103 *> \date September 2012
104 *
105 *> \ingroup complex16OTHERauxiliary
106 *
107 * =====================================================================
108  SUBROUTINE zlartv( N, X, INCX, Y, INCY, C, S, INCC )
109 *
110 * -- LAPACK auxiliary routine (version 3.4.2) --
111 * -- LAPACK is a software package provided by Univ. of Tennessee, --
112 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
113 * September 2012
114 *
115 * .. Scalar Arguments ..
116  INTEGER incc, incx, incy, n
117 * ..
118 * .. Array Arguments ..
119  DOUBLE PRECISION c( * )
120  COMPLEX*16 s( * ), x( * ), y( * )
121 * ..
122 *
123 * =====================================================================
124 *
125 * .. Local Scalars ..
126  INTEGER i, ic, ix, iy
127  COMPLEX*16 xi, yi
128 * ..
129 * .. Intrinsic Functions ..
130  INTRINSIC dconjg
131 * ..
132 * .. Executable Statements ..
133 *
134  ix = 1
135  iy = 1
136  ic = 1
137  DO 10 i = 1, n
138  xi = x( ix )
139  yi = y( iy )
140  x( ix ) = c( ic )*xi + s( ic )*yi
141  y( iy ) = c( ic )*yi - dconjg( s( ic ) )*xi
142  ix = ix + incx
143  iy = iy + incy
144  ic = ic + incc
145  10 continue
146  return
147 *
148 * End of ZLARTV
149 *
150  END