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Diffstat (limited to 'sys/vops/afftxr.x')
| -rw-r--r-- | sys/vops/afftxr.x | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/sys/vops/afftxr.x b/sys/vops/afftxr.x new file mode 100644 index 00000000..b09ae0f5 --- /dev/null +++ b/sys/vops/afftxr.x @@ -0,0 +1,27 @@ +# 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 |