fig7-37.m

数字信号处理（机械工业出版社）的源码

% fig7-37
N = 4; passband = [.4 .6]; ripple = .1;
[Bb,Ab] = butter(N, passband);
[Bc,Ac] = cheby1(N, ripple, passband);
h = [abs(hh) abs(freqz(Bb,Ab,n)) abs(freqz(Bc,Ac,n))];
plot(ff,h)
legend({'YuleWalk','Butterworth','Chebyshev'});
title('Filter Performance')
xlabel('Frequency (Hz)')
ylabel('Magnitude')