subroutine cswapf (n,cx,incx,cy,incy) c c interchanges two vectors. c jack dongarra, linpack, 3/11/78. c modified 12/3/93, array(1) declarations changed to array(*) c complex cx(*),cy(*),ctemp integer i,incx,incy,ix,iy,n c if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments not equal c to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n ctemp = cx(ix) cx(ix) = cy(iy) cy(iy) = ctemp ix = ix + incx iy = iy + incy 10 continue return c c code for both increments equal to 1 20 do 30 i = 1,n ctemp = cx(i) cx(i) = cy(i) cy(i) = ctemp 30 continue return end