B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

2.8 MATLAB Exercises 47
Basic Signals and Signal Graphing
Basic functions can be defined by using MATLAB's m-files. We gave three MATLAB programs
that implement three basic functions when a time vector t is provided:
us tep . m implements the unit step function u(t)
rect . m implements the standard rectangular function rect(t)
triangl . m implements standard triangle function (t)
% (file name : ustep .m)
% The unit step function is a function of time 't' .
% Usage y ustep(t)
%
% ustep (t)
% ustep (t)
%
0
1,
if t < 0
if t >= 1
% t - must be real-valued and can be a vector or a matrix
%
function y=ustep (t)
y = (t>=O) ;
end
% (file name : rect .m)
% The rectangular function is a function of time 't' .
%
% Usage y = rect (t)
% t - must be real-valued and can be a vector or a matrix
%
% rect (t)
% rect (t)
%
1,
0,
if l tl < o.5
if l t l > o.5
function y=rect (t)
y =(sign (t+0 .5)-sign(t- 0.5) >0) ;
end
% (file name : triangl .m)
% The triangle function is a function of time 't' .
%
% triangl (t)
% triangl (t)
%
% Usage y
1- l t l , if l t l < 1
O, if l t l > l
triangl (t)
% t - must be real-valued and can be a vector or a matrix
%