urect.m

很多matlab的源代码

function y=urect(t,a)
% URECT  Unit Rectangle Function.
%
%        Y=URECT(t) generates a rectangle of height=1, width=1,centered at t=0.
%	 The end-values of urect(t) at t=0.5 and t=0.5 equal 1.
%
%        Y=URECT(T,A) generates a rectangle with end-values = A.  
%
%        URECT (with no input arguments) invokes the following example:
%
%          % Plot 2*urect((t-1)/3,0.5), a CT rect with height=2, width=3, 
%	   % centered at t=1, and end-values = 0.5
%          >>t=-4:.05:4;
%          >>yt=2*urect((t-1)/3,0.5);
%          >>plot(t,yt),grid
%
%        See Also: UDELTA, URAMP, USTEP, TRI


% ADSP Toolbox: Version 2.0 
% For use with "Analog and Digital Signal Processing", 2nd Ed.
% Published by PWS Publishing Co.
%
% Ashok Ambardar, EE Dept. MTU, Houghton, MI 49931, USA
% http://www.ee.mtu/faculty/akambard.html
% e-mail: [e-mail]
% Copyright (c) 1998


if nargin==0,
 help urect
 disp('Strike a key to see results of the example')
 pause
 t0=-4:.05:4;
 yt=2*urect((t0-1)/3,0.5);
  v=matverch;
 if v < 4, eval('clg');else,eval('clf');end

 axis([-4 4 0 3])
 plot(t0,yt)
 axis([-4 4 0 3])
 grid
 hold off
 return
end

z=abs(t);
if nargin == 1,
 y=(z<=0.5);
elseif nargin == 2,
 y=(z<0.5)+a*(z==0.5);
elseif nargin > 2,
 error('Too many input arguments');
end