example7_2.m

西交大刘树棠写的《数字信号处理》那本书的所有源代码

h=[-4,1,-1,-2,5,6,5,-2,-1,1,-4];
M=length(h);n=0:M-1;
[Hr,w,a,L]=Hr_Type1(h);
a,L
amax=max(a)+1;
amin=min(a)-1;
subplot(2,2,1);stem(n,h);axis([-1 2*L+1 amin amax])
xlabel('n');ylabel('h(n)');title('impuse response')
subplot(2,2,3);stem(n:L,a);axis([-1 2*L+1 amin amax])
xlabel('n');ylabel('a(n)');title('a(n) coefficient')
subplot(2,2,2);plot(w/pi,Hr);grid
xlabel('frequency in pi units');ylabel('Hr')
title('Type-1 Amplitude Response')
subplot(2,2,4);zplane(h,1)