dtft_r_win.m

经典《信号与系统》教程的matlab例程,对深入理解信号与系统相关概念有很大帮助

%==========================================================================
%  Name：DTFT.m
%  The program compute the DTFT of discrete-time sequence x(n),
%  and plot the curves.
%==========================================================================
clear;
n=-20:20;
f=u(n+6)-u(n-7);%input('Type in the expression of sequence x(n)：');
W1=pi;                           
N=512;           
k=-N:N;                              
W=k*W1/(N);                           
F=f*exp(-j*n'*W);

subplot(2,1,1);stem(n,f,'.');grid on;
xlabel('Index n');
title('The time window function RN(n)');
subplot(2,1,2);plot(W,F);grid on;
xlabel('frequency (*pi)');
title('The frequency response of the window RN(n)');