example7_5.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,-6,-5,2,1,-1,4];
M=length(h);n=0:M-1;
[Hr,w,d,L]=Hr_Type4(h);
d,L
dmax=max(d)+1;
dmin=min(d)-1;
subplot(2,2,1);stem(n,h);axis([-1 2*L+1 dmin dmax])
xlabel('n');ylabel('h(n)');title('impuse response')
subplot(2,2,3);stem(1:L,d);axis([-1 2*L+1 cmin dmax])
xlabel('n');ylabel('d(n)');title('d(n) coefficient')
subplot(2,2,2);plot(w/pi,Hr);grid
xlabel('frequency in pi units');ylabel('Hr')
title('Type-4 Amplitude Response')
subplot(2,2,4);zplane(h,1)