example7_5.m

This complete matlab for neural network

%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，生成旋转对称的二维高斯窗函数
win = fspecial('gaussian',21,2);
win = win ./ max(win(:));  % 将窗口的最大值归1.
mesh(win)
%最后，用前一步生成的窗函数设计滤波器，代码如下：
h1 = fwind2(Hd,win);
freqz2(h1)