ms10r4.m

《数字信号处理实验(MATLAB版)》这

b=[0.187632,0, -0.241242,0,0.241242,0,-0.187632];
a=[1,0,0.602012,0, 0.495684, 0,0.035924];
[db,mag,pha,grd,w]=freqz_m(b,a);
subplot(2,2,1),plot(w/pi,mag);grid %作绝对幅度频响图
axis([0,1,1.1*min(mag),1.1*max(mag)]);
title('幅频特性（V）');
subplot(2,2,2),plot(w/pi,pha);grid  %作相位频响图
axis([0,1,1.1*min(pha),1.1*max(pha)]);
title('相频特性');
subplot(2,2,3),plot(w/pi,db);grid   %作相对幅度频响图
axis([0,1,-60,5]);
title('幅频特性（dB）');
subplot(2,2,4),plot(w/pi,grd);grid  %作系统的群迟延图
title('群迟延');
axis([0,1,0,7]);