라 하자. 진폭 응답와, H(z)의 영점위치를 구해보자.

ex7_4.cem

/*   Chapter 7: Example 7.4   Type-1 Linear phase FIR filter*/
 
 h = [-4,1,-1,-2,5,6,5,-2,-1,1,-4];
 M = length(h); n = 0:M-1;
 [Hr,w,a,L] = Hres_t1(h);
 a
 L
 amax = max(a)+1; amin = min(a)-1;
 subplot(2,2,1); 
stem(n,h);
 xtitle("n"); ytitle("h(n)"); title("Impulse Response") 
subplot(2,2,2);
plot(w/pi,Hr);
 xtitle("frequency in pi units"); ytitle("Hr") title("Type-1 Amplitude Response") 
subplot(2,2,3); 
stem(0:L,a);
 xtitle("n"); ytitle("a(n)"); title("a(n) coefficients") 
subplot(2,2,4);
 zplane(h,1) title("Pole-Zero Plot")