usage: y = rectpuls(t, w)

Generate a rectangular pulse over the interval [-w/2,w/2), sampled at
times t.  This is useful with the function pulstran for generating a
series pulses.

Example
fs = 11025;  # arbitrary sample rate
f0 = 100;    # pulse train sample rate
w = 0.3/f0;  # pulse width 3/10th the distance between pulses
auplot(pulstran(0:1/fs:4/f0, 0:1/f0:4/f0, 'rectpuls', w), fs);

See also: pulstran