DTFT 의 다른 샘플을 구해보자.

ex5_7.cem

// b) 4-point DFT
x = [1,1,1,1];
subplot(1,1,1);
// a) DTFT
w = [0:500:1]*2*pi/500;
[H] = freqz(x,1,w);
magH = abs(H); phaH = angle(H); phaH(126)=-47.5841*pi/180;
 
N = 4; w1 = 2*pi/N; k = 0:N-1;
X = dft(x,N);
magX = abs(X); phaX = angle(X)*180/pi

subplot(2,1,1);plot(w*N/(2*pi),magH,"--"); 
holdon
stem(k,magX);
xtitle("k");
ytitle("|X(k)|"); title("Magnitude of the DFT: N=4");
holdoff
subplot(2,1,2);plot(w*N/(2*pi),phaH*180/pi,"--");
holdon
stem(k,phaX,"-");
 
xtitle("k");
ytitle("Degrees"); title("Angle of the DFT: N=4")