www.pudn.com > DSP3_MATLAB.rar > exa030102.m

%---------------------------------------------------------------------------- 
% exa030102, for example 3.1.2 
% to obtain the Fourier transform of a continuous rectangle  signal;  
% 计算连续方波信号的付里叶变换 
%---------------------------------------------------------------------------- 
clear all； 
 
% 下面说明如何画出一个sinc函数； 
tao=0.2;A=5; 
s=pi*tao; 
A1=A*tao; 
for f=1:60 
   f1=f-30; 
   sf1=s*f1; 
   if sf1==0; 
      x(f)=1; 
   else 
      x(f)=sin(sf1)/sf1; 
      end  
end 
f=-29:30;    
 
subplot(211) 
plot(f,x,f,zeros(size(x)));grid on