function out = rectw(t,tau)
%  This function is the pulse function symmetric
%  about 0 with width TAU and height 1/TAU:
%
%   sig = rectw(t,tau), where SIG and T are vectors of the same dimension.
%
%   elements of SIG are either 0 or 1/TAU corresponding to elements of T
%   whose absolute values are greater than TAU/2 and
%   those that are less than or equal to TAU/2, respectively.
%
%
%       written by Kevin D. Donohue  2/93
%
out = zeros(size(t));                              % set up output array
elm_1 = find((t-tau/2 <= 0) & (t+tau/2 >=0));      % assign zero function values
out(elm_1) = (1/(abs(tau)+eps))*ones(size(elm_1));   % assign unity function values