DFT/IDFT Demo

Displays a discrete signal, its DFT, and the IDFT reconstructed signal. Press any key for next parameter.

clf;
L = 100;
for (L_factor = 1:1:6)
%L_factor = 3;
N_factor = 1;
L = round(L*L_factor);
n = [0:1:L-1];
x = sin(pi/1000*(n.*n));
 
subplot(3,1,1);
stem(n,x);
title ('x[n]');
 
subplot(3,1,2);
y = fft(x,L*N_factor);
plot(abs(y));
title ('DFT');
 
subplot(3,1,3);
xr = ifft(y);
stem(n,xr(1:L));
title ('IDFT');
 
pause;
end