LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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◆ 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*