demo2.m

这是一个 York大学开发的FDTD代码。很好用的工具

disp('Demonstrate FFT for rectangular pulse train')


disp('Generate time and frequency steps')
Ts=Tp/(N)
fs=1/Ts
f=linspace(0,fs*(N-1)/N,N);
disp('Generate time steps for one period (t)');
t=linspace(0,Tp*(N-1)/N,N);

disp('Generate time sequence (x) and plot it against time (t)')
x=prect(t,Tw,Tp);
plot(t,x,'+')
title ('Original pulse train')
xlabel('Time')
input('Any key to continue')

disp('Generate FFT (X) of time series (x) and plot the real and imaginary parts');
X=Ts*fft(x);
plot(f,real(X),'o',f,imag(X),'*')
title('DFT of pulse train - real o, imag *')
xlabel('Frequency')
input('Any key to continue')

disp('Generate time sequence (xr) from FFT (X) and plot it against time (t)')
xr=1/Ts*ifft(X);
plot(t,x,'+',t,real(xr),'o')
title('Pulse train + and Inverse Transform o (DFT)')
xlabel('Time')