ex0824.m

数字信号处理（机械工业出版社）的源码

% Chapter 08: Example 8.24 Design a filter
n=135;
f = [0 0.2 0.4 0.7 0.9 1]; 
a = [0 0.5 0 1 0];
up=[0.005 0.51 0.03 1.02 0.05]
lo=[-0.005 0.49 -0.03 0.98 -0.05];
b=fircls(n,f,a,up,lo);
[h,w]=freqz(b,1,512,2);
plot(w,abs(h)); grid on
xlabel('Normalized Frequency'); ylabel('magnitude(dB)');