# [Matrix-SIG] inverse fft2d (complex case)

**Frank Horowitz
**
frank@ned.dem.csiro.au

*Sat, 14 Nov 1998 11:18:46 +0800*

G'Day folks,
I've been using NumPy (and Python) for a bit over a week now. To all
who've contributed, I'd like to say "Great Job"! It's truly a pleasure
to use...
Even though it may be too trivial to warrant comment, I've implemented
something that I felt the acute lack of in the LLNL NumPy distribution:
the inverse of a 2d FFT (at least for the complex valued case; I hope
to follow up with the equivalent real-valued inverse, once I grok the
way that the wavenumbers are packed upon output from the forward
2dfft). Without further ado, here is the code (all 2 lines of it :-)
def inverse_fft2d(a, s=None, axes=(-2,-1)):
return _raw_fft2d(a,s,axes,inverse_fft)
I suppose it's debatable whether such a trivial extension belongs in
the distribution. Indeed it's absence suggests some deeper issues (that
I'm missing) have already been debated, and somebody decided that the
implementation of an inverse properly belongs with the individual
users. If so, pardon me for the intrusion :-)
Obviously, I've also implemented ways of determining the appropriate
wavenumbers, and will be happy to post them if anyone is interested.
Cheers,
Frank Horowitz