9.m

已知一个LTI系统的差分方程为： y[n]-1.143*y[n-1]+0.4128*y[n-2]=0.0675*x[n]+0.1349*x[n-1]+0.0675*x[n-2] 初始条件y(-1

b=1.031*[1,0,1];
a=[1,0,1.0621];
zplane(b,a);
[H,w]=freqz(b,a,250);
plot(w/pi,abs(H));