freqz_m.m

西交大刘树棠写的《数字信号处理》那本书的所有源代码

function [db,mag,pha,grd,w]=freqz_m(b,a);
[H,w]=freqz(b,a,1000,'whole');
H=(H(1:1:501))';w=(w(1:1:501))';
mag=abs(H);
db=20*log10((mag+eps)/max(mag));
pha=angle(H);
grd=grpdelay(b,a,w);
subplot(2,2,1);plot(w/pi,mag);
subplot(2,2,2);plot(w/pi,db);
subplot(2,2,3);plot(w/pi,pha);