test patterns, probably useful for FFT (FFTW):

# generate tilted stripes:
r.mapcalc test="if( (row() + col())%50 > 25,1,null())"
d.rast test

#fft them: result should look perpendicular and following one "line" only:
i.fft in=test real=real ima=img
d.rast real
d.rast img

-> check carefully

i.ifft real=real ima=img out=test_back
# compare result to original:
d.rast test_back
d.rast test

(oops, i.ifft writes 0 instead of NULL!)
-> BUG

$Id: TESTS,v 1.2 2002/01/22 04:51:05 glynn Exp $
