example7_3.m

This complete matlab for neural network

%分别采用Hamming窗、Bartlett窗、Hanning窗和Blackman窗设计近似圆对称的
%带通滤波器，通频带为[0.1,0.5]。
%首先，创建包含了期望的带通响应的矩阵Hd
[f1,f2] = freqspace(21,'meshgrid');
Hd = ones(21);
r = sqrt(f1.^2 + f2.^2);
Hd((r<0.1)|(r>0.5)) = 0;
colormap(jet(64))
mesh(f1,f2,Hd) 
%然后，分别用一维Hamming窗、Bartlett窗、Hanning窗和Blackman窗设计滤波器，
%代码如下：
h1 = fwind1(Hd,hamming(21));
figure,freqz2(h1)
h2 = fwind1(Hd, bartlett (21));
figure,freqz2(h2)
h3 = fwind1(Hd, hanning (21));
figure,freqz2(h3)
h4 = fwind1(Hd, blackman (21));
figure,freqz2(h4)