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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
# AFFTXR -- Forward fourier transform (complex transform, real arrays).
# The fourier transform of the real arrays SR and SI containing complex data
# pairs is computed and the complex transform coefficients are returned in
# the real arrays FR and FI. The transformation may be performed in place if
# desired. NPIX must be a power of 2.
procedure afftxr (sr, si, fr, fi, npix)
real sr[ARB], si[ARB] # data, spatial domain (input)
real fr[ARB], fi[ARB] # transform, frequency domain (output)
int npix
int ier
begin
# The following are no-ops if the transform is being performed
# in place.
call amovr (sr, fr, npix)
call amovr (si, fi, npix)
# Compute the forward transform.
call fft842 (0, npix, fr, fi, ier)
if (ier == 1)
call fatal (1, "afftxr: npix not a power of 2")
end
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