LAPACK 3.12.0 LAPACK: Linear Algebra PACKage
Searching...
No Matches
zswap.f
Go to the documentation of this file.
1*> \brief \b ZSWAP
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 ZSWAP(N,ZX,INCX,ZY,INCY)
12*
13* .. Scalar Arguments ..
14* INTEGER INCX,INCY,N
15* ..
16* .. Array Arguments ..
17* COMPLEX*16 ZX(*),ZY(*)
18* ..
19*
20*
21*> \par Purpose:
22* =============
23*>
24*> \verbatim
25*>
26*> ZSWAP interchanges two vectors.
27*> \endverbatim
28*
29* Arguments:
30* ==========
31*
32*> \param[in] N
33*> \verbatim
34*> N is INTEGER
35*> number of elements in input vector(s)
36*> \endverbatim
37*>
38*> \param[in,out] ZX
39*> \verbatim
40*> ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
41*> \endverbatim
42*>
43*> \param[in] INCX
44*> \verbatim
45*> INCX is INTEGER
46*> storage spacing between elements of ZX
47*> \endverbatim
48*>
49*> \param[in,out] ZY
50*> \verbatim
51*> ZY is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
52*> \endverbatim
53*>
54*> \param[in] INCY
55*> \verbatim
56*> INCY is INTEGER
57*> storage spacing between elements of ZY
58*> \endverbatim
59*
60* Authors:
61* ========
62*
63*> \author Univ. of Tennessee
64*> \author Univ. of California Berkeley
65*> \author Univ. of Colorado Denver
66*> \author NAG Ltd.
67*
68*> \ingroup swap
69*
70*> \par Further Details:
71* =====================
72*>
73*> \verbatim
74*>
75*> jack dongarra, 3/11/78.
76*> modified 12/3/93, array(1) declarations changed to array(*)
77*> \endverbatim
78*>
79* =====================================================================
80 SUBROUTINE zswap(N,ZX,INCX,ZY,INCY)
81*
82* -- Reference BLAS level1 routine --
83* -- Reference BLAS is a software package provided by Univ. of Tennessee, --
84* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
85*
86* .. Scalar Arguments ..
87 INTEGER INCX,INCY,N
88* ..
89* .. Array Arguments ..
90 COMPLEX*16 ZX(*),ZY(*)
91* ..
92*
93* =====================================================================
94*
95* .. Local Scalars ..
96 COMPLEX*16 ZTEMP
97 INTEGER I,IX,IY
98* ..
99 IF (n.LE.0) RETURN
100 IF (incx.EQ.1 .AND. incy.EQ.1) THEN
101*
102* code for both increments equal to 1
103 DO i = 1,n
104 ztemp = zx(i)
105 zx(i) = zy(i)
106 zy(i) = ztemp
107 END DO
108 ELSE
109*
110* code for unequal increments or equal increments not equal
111* to 1
112*
113 ix = 1
114 iy = 1
115 IF (incx.LT.0) ix = (-n+1)*incx + 1
116 IF (incy.LT.0) iy = (-n+1)*incy + 1
117 DO i = 1,n
118 ztemp = zx(ix)
119 zx(ix) = zy(iy)
120 zy(iy) = ztemp
121 ix = ix + incx
122 iy = iy + incy
123 END DO
124 END IF
125 RETURN
126*
127* End of ZSWAP
128*
129 END
subroutine zswap(n, zx, incx, zy, incy)
ZSWAP
Definition zswap.f:81