% suplane | sufilter f=10,20,30,60 amps=0,1,1,0 | suxwigb title="10,20,30,60 hz bandpass" &

% suplane | sufilter f=10,20,30,60 amps=1,0,0,1 | suxwigb title="10,20,30,60 hz bandreject" &

% suplane | sufilter f=10,20,30,60 amps=1,1,0,0 | suxwigb title="10,20 hz lowpass" &

% suplane | sufilter f=50,60,70 amps=1,0,1 | suxwigb title="60 hz notch" &

The filter is polygonal, with the corners of the polygon defined by
the vector of frequency values defined by array of **f=** values,
and a collection of amplitude values, defined by the array of **amps=**
values. The amplitudes may be any floating point numbers greater than,
or equal to zero. The only rule is that there must be the same number
of **amps** values, as **f** values. The segments are sine-squared
tapered between **f** values of different amplitude. It is
best to select bf f values such that tapering to zero is done
over an octave to prevent ringing.

With **suplane**, **sufilter** provides a way of easily
generating bandlimited testpattern data in SU format.