exa5_19.m

新版Matlab 7辅助信号处理技术与应用

%--------------------------------------------------------------------------
% exa060602_fir2.m,   for example 6.6.2;
% to test fir2 and to design multiband FIR filter;
%-------------------------------------------------------------------------

f =[0 0.125 0.125 0.250 0.250 0.500 0.500 0.750 0.750 1.00];
m=[1 1 0.5 0.5 0.25 0.25 1/6 1/6 0.125 0.125];
b = fir2(60,f,m);
[h,w] = freqz(b);
plot(f,m,'k-',w/pi,abs(h),'k.')
grid on;
title('实际滤波器和理想滤波器幅度频率特性比较');
xlabel('归一化频率(Wn)');
ylabel('幅度');
legend('理想滤波器','实际滤波器')