function out = sinc2(t,tau)
%  This function is the squared sinc window 
%  with main lobe width 2*TAU:
%
%   sig = sinc2(t,tau), where SIG and T are vectors of the same dimension.
%
%   elements of SIG are (abs(sin(pi*T/TAU)./ (pi*T/TAU)).^2. 
%
%
%        written by Kevin D. Donohue    2/93
%
%
out = zeros(size(t));   % set up output array

if min(abs(t)) == 0,     %  if t-axis includes a 0, take limit
   elm_1 = find(t == 0);   % find place where t-axis is zero
   out(elm_1) = 1;     %   Special case for t=0
end

elm_1 = find(t ~= 0);   % find all the other points

out(elm_1) = abs(sin(pi*t(elm_1)/tau)./(pi*t(elm_1)/tau)).^2;    % plug into sinc