astropy/astropy — pull request #2792 by keflavich (2014-07-24 08:05:28+00:00)
Title: Speed up convolve_fft in a few small ways

As suggested by @jtaylor:

1. Pad to nearest power of 2, 3, 5 (if scipy is available)
2. Allow real ffts, which will use less memory and may be better optimized. This is awkward to use for now.

WIP - should have feedback before merging is considered