라 하자. 진폭 응답와, 의 영점위치를 구해보자.

ex7_7.cem

/*    Chapter 7: Example 7.7    Type-4 Linear phase FIR filter*/
 
 h = [-4,1,-1,-2,5,6,-6,-5,2,1,-1,4];
 M = length(h); n = 0:M-1;
 [Hr,w,d,L] = Hres_t4(h);
 d
 L
 
 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-2 Amplitude Response") 
 subplot(2,2,3); 
 stem(1:L,d);
 xtitle("n"); ytitle("d(n)"); title("d(n) coefficients") 
 subplot(2,2,4);
 plane_z(h,1) title("Pole-Zero Plot")