page_413.m

Signal and Sytem Using Matlab 书的源代码 注释详尽 m文件

%设计一个切比雪夫1型高通滤波器，其模拟截止频率wc=2
%page_413
N=2;%number of poles
Rp=3;%passband ripple
T=.2;%sampling  period
wc=2;%analog cutoff frequency
Wc=wc*T/pi;%normalized digital cutoff frequency
[numd,dend]=cheby1(N,Rp,Wc,'high');
numd = real(numd) % strips off negligible imag part introduced in roundoff
dend = real(dend)
W = -pi:2*pi/200:pi;
H = freqz(numd,dend,W);
plot(W,abs(H))
% Figure in text uses command plot(w/pi,abs(H))
%   and the pi's are added by hand.
axis([-pi pi 0 1])
title('Figure 10.9')
ylabel('|Hd|')
xlabel('\Omega')