changes nyquist cutoff
changes nyquist cutoff

with this, we make the frequency cutoff 5% under the nyquist
frequency (i.e., .475 cpp instead of .5), so that we have a bit of a
buffer. we *really* don't want aliasing and things aren't quite exact

billbrod/spatial-frequency-preferences,billbrod/spatial-frequency-preferences,billbrod/spatial-frequency-preferences