사이에 있는 501개 등간격 점들에서 다음의 신호 을 그려보자.

ex3_4.cem

 n = -1:3; x = 1:5;                    /* sequence x(n) */
 k = 0:500; w = (pi/500)*k;            /* [0, pi] axis divided into 501 points. */
 X = x * (exp(-j*pi/500)) .^ (n'*k);       /* DTFT using matrix-vector product */
 magX = abs(X); angX = angle(X);
 realX = real(X); imagX = imag(X);
 subplot(2,2,1); plot(w/pi,magX);
 xtitle("frequency in pi units"); title("Magnitude Part"); ytitle("Magnitude") subplot(2,2,3); plot(w/pi,angX);
 xtitle("frequency in pi units"); title("Angle Part"); ytitle("Radians") subplot(2,2,2); plot(w/pi,realX);
 xtitle("frequency in pi units"); title("Real Part"); ytitle("Real") subplot(2,2,4); plot(w/pi,imagX);
 xtitle("frequency in pi units"); title("Imaginary Part"); ytitle("Imaginary")