LAPACK  3.10.0
LAPACK: Linear Algebra PACKage

◆ cswap()

subroutine cswap ( integer  N,
complex, dimension(*)  CX,
integer  INCX,
complex, dimension(*)  CY,
integer  INCY 
)

CSWAP

Purpose:
   CSWAP interchanges two vectors.
Parameters
[in]N
          N is INTEGER
         number of elements in input vector(s)
[in,out]CX
          CX is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]INCX
          INCX is INTEGER
         storage spacing between elements of CX
[in,out]CY
          CY is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
[in]INCY
          INCY is INTEGER
         storage spacing between elements of CY
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Further Details:
     jack dongarra, linpack, 3/11/78.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 80 of file cswap.f.

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 CX(*),CY(*)
91 * ..
92 *
93 * =====================================================================
94 *
95 * .. Local Scalars ..
96  COMPLEX CTEMP
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  ctemp = cx(i)
105  cx(i) = cy(i)
106  cy(i) = ctemp
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  ctemp = cx(ix)
119  cx(ix) = cy(iy)
120  cy(iy) = ctemp
121  ix = ix + incx
122  iy = iy + incy
123  END DO
124  END IF
125  RETURN
126 *
127 * End of CSWAP
128 *