% Chapter 7:例 7.4 1-型線性相位FIR濾波器
%
subplot(1,1,1)
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);
amax = max(a)+1; amin = min(a)-1;
subplot(2,2,1); stem(n,h); axis([-1 2*L+1 amin amax])
text(2*L+1.5,amin,'n'); ylabel('h(n)'); title('脈沖響應(yīng)')
subplot(2,2,3); stem(0:L,a); axis([-1 2*L+1 amin amax])
xlabel('n'); ylabel('a(n)'); title('a(n) 系數(shù)')
subplot(2,2,2);plot(w/pi,Hr);grid
text(1.05,-20,'頻率pi'); ylabel('Hr')
title('1-型振幅響應(yīng)')
subplot(2,2,4);pzplotz(h,1)
title('零極點分布')