18t.m

来自「包含50个数字信号处理方面的matlab程序」· M 代码 · 共 27 行

Wn=2*pi*100;
fs=1000;
[b,a]=butter(6,Wn,'s');
[bz,az]=impinvar(b,a,fs);
[db,mag,pha,grd,w]=freqz_m(bz,az);
subplot(2,2,1);
plot(w/pi,db);
title('系统的幅频响应');
axis([0,1,-50,5]);
subplot(2,2,2);
plot(w/pi,pha);
title('系统的相频响应');
%Filter
x=[-4,-2,0,-4,-6,-4,-2,-4,-6,-6,-4,-4,-6,-6,...
    -2,6,12,8,0,-16,-38,-60,-84,-90,-66,-32,...
    -4,2,-4,8,12,12,10,6,6,6,4,0,0,0,0,0,-2,...
    -4,0,0,0,-2,-2,0,0,-2,-2,-2,-2,0];
y=filter(bz,az,x);
N=56;
n=0:N-1;
subplot(2,2,3);
plot(n,x);
title('输入波形');
subplot(2,2,4);
plot(n,y);
title('输出波形');