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