% Chapter 05: Example 05.07: Zero-padding Example%subplot(1,1,1);x = [1,1,1,1];%% a) DTFTw = [0:1:500]*2*pi/500;[H] = freqz(x,1,w);magH = abs(H); phaH = angle(H); phaH(126)=-47.5841*pi/180;%% b) 8-point DFTN = 8; w1 = 2*pi/N; k = 0:N-1;x = [x, zeros(1,4)];X = dft(x,N);magX = abs(X), phaX = angle(X)*180/pisubplot(2,1,1);plot(w*N/(2*pi),magH,'--'); axis([-0.1,8.1,-1,5]); hold onstem(k,magX);xlabel('k');ylabel('|X(k)|'); title('Magnitude of the DFT: N=8')hold offsubplot(2,1,2);plot(w*N/(2*pi),phaH*180/pi,'--');axis([-0.1,8.1,-200,200]); hold onstem(k,phaX);xlabel('k');ylabel('Degrees'); title('Angle of the DFT: N=8');pause%print -deps2 me0507a.eps% c) 16-point DFTsubplot(1,1,1)N = 16; w1 = 2*pi/N; k = 0:N-1;x = [x, zeros(1,8)];X = dft(x,N);magX = abs(X), phaX = angle(X)*180/pisubplot(2,1,1);plot(w*N/(2*pi),magH,'--'); axis([-0.1,16.1,-1,5]); hold onstem(k,magX);xlabel('k');ylabel('|X(k)|'); title('Magnitude of the DFT: N=16')hold offsubplot(2,1,2);plot(w*N/(2*pi),phaH*180/pi,'--');axis([-0.1,16.1,-200,200]); hold onstem(k,phaX);xlabel('k');ylabel('Degrees'); title('Angle of the DFT: N=16')%print -deps2 me0507b.eps