function y = amrect(N,t0,T);%AMRECT	Generate rectangular amplitude modulation.%	Y = AMRECT(N,T0,T) generates a rectangular amplitude modulation %	centered on a time T0, and with a spread proportional to T.%	This modulation is scaled such that Y(T0)=1.% %	N  : number of points.%	T0 : time center		(default : N/2).%	T  : time spreading		(default : 2*sqrt(N)).%	Y  : signal.%%	Examples:%	 z=amrect(160);plot(z);%	 z=amrect(160,90,40);plot(z);%	 z=amrect(160,180,70);plot(z);%%	See also AMEXPO1S, AMEXPO2S, AMGAUSS, AMTRIANG.%	F. Auger, July 1995.%	Copyright (c) 1996 by CNRS (France).%%	------------------- CONFIDENTIAL PROGRAM -------------------- %	This program can not be used without the authorization of its%	author(s). For any comment or bug report, please send e-mail to %	f.auger@ieee.org if (nargin == 0), error ( 'The number of parameters must be at least 1.' );elseif (nargin == 1), t0=N/2; T=2*sqrt(N);elseif (nargin ==2), T=2*sqrt(N);end;if (N<=0), error('N must be greater or equal to 1.');else tmt0=(1:N)'-t0; y = (abs(tmt0) <= 0.5*T*sqrt(3.0/pi));end;