ex0426b.m

数字信号处理（机械工业出版社）的源码

% Chapter 4: Example 4.11:
%  zplane function:
%
b = [1,0]; a = [1, -0.9];
w=[0:100]*pi/100;
H=freqz(b,a,w);
magH=abs(H);phaH=angle(H);
subplot(211);plot(w/pi,magH);grid
xlabel('frequency in pi units');ylabel('Magnitude');
title('Magnitude Response')
subplot(212);plot(w/pi,phaH/pi);grid
xlabel('frequency in pi units');ylabel('Phase in pi units');
title('Phase Response')