fg_06_20.m

英文书《Digital Signal Processing with Examples in MATLAB》附带的MATLAB实例

% fg_06_20 - Comb filter output.  
N=100; r=.99; s=[1:2:16];
Nx=300; k=0:Nx-1;
x=(1+3*k/Nx).*sin(2*pi*k.*(.05+(k/Nx)*.06));
x=comb(N,s,r,x);
inc=1/N;

sp_fig(1,9,5);
axis([0 Nx 0 (max(s)+1)*inc]); grid on;
set(gca,'fontsize',16);
for n=1:length(s);
   xplot=s(n)/N+(inc/max(x(n,:)))*x(n,:);
   line(0:Nx-1,xplot,'color','r');
end
xlabel('Sample number'); ylabel('Frequency (Hz-s)');
title('Spectrogram of x');
set(gca,'position',[0.1 0.13 0.97-.1 0.92-.13])
set(gca,'fontsize',16);