LAPACK  3.6.1 LAPACK: Linear Algebra PACKage
 subroutine cswap ( integer N, complex, dimension(*) CX, integer INCX, complex, dimension(*) CY, integer INCY )

CSWAP

Purpose:
`   CSWAP interchanges two vectors.`
Date
November 2011
Further Details:
```     jack dongarra, linpack, 3/11/78.
modified 12/3/93, array(1) declarations changed to array(*)```

Definition at line 52 of file cswap.f.

52 *
53 * -- Reference BLAS level1 routine (version 3.4.0) --
54 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
55 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
56 * November 2011
57 *
58 * .. Scalar Arguments ..
59  INTEGER incx,incy,n
60 * ..
61 * .. Array Arguments ..
62  COMPLEX cx(*),cy(*)
63 * ..
64 *
65 * =====================================================================
66 *
67 * .. Local Scalars ..
68  COMPLEX ctemp
69  INTEGER i,ix,iy
70 * ..
71  IF (n.LE.0) RETURN
72  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
73 *
74 * code for both increments equal to 1
75  DO i = 1,n
76  ctemp = cx(i)
77  cx(i) = cy(i)
78  cy(i) = ctemp
79  END DO
80  ELSE
81 *
82 * code for unequal increments or equal increments not equal
83 * to 1
84 *
85  ix = 1
86  iy = 1
87  IF (incx.LT.0) ix = (-n+1)*incx + 1
88  IF (incy.LT.0) iy = (-n+1)*incy + 1
89  DO i = 1,n
90  ctemp = cx(ix)
91  cx(ix) = cy(iy)
92  cy(iy) = ctemp
93  ix = ix + incx
94  iy = iy + incy
95  END DO
96  END IF
97  RETURN