% Chapter 7: Rectangular Window Gibbs Phenomenon%subplot(1,1,1); N = 1000;% M = 7M = 7; alpha = (M-1)/2;n = -alpha:alpha;w = ones(1,M);omega = (2*pi/N)*[-N/2:N/2];Wr = real(w*(exp(-j*n'*omega)));db = 20*log10(abs(Wr)/max(Wr));IntWr = cumsum(Wr)/N;%% plotssubplot(2,2,1); plot(omega/pi,IntWr);axis([-1,1,-0.15,1.15]);title('M = 7')xlabel('frequency in pi units'); ylabel('Integrated Amplitude Response')set(gca,'YTickMode','manual','YTick',[0,1])set(gca,'XTickMode','manual','XTick',[-1,0,1]); grid%% M = 21M = 21; alpha = (M-1)/2;n = -alpha:alpha;w = ones(1,M);omega = (2*pi/N)*[-N/2:N/2];Wr = real(w*(exp(-j*n'*omega)));db = 20*log10(abs(Wr)/max(Wr));IntWr = cumsum(Wr)/N;%% plotssubplot(2,2,2); plot(omega/pi,IntWr);axis([-1,1,-0.15,1.15]);title('M = 21')xlabel('frequency in pi units'); ylabel('Integrated Amplitude Response')set(gca,'YTickMode','manual','YTick',[0,1])set(gca,'XTickMode','manual','XTick',[-1,0,1]); grid%% M = 51M = 51; alpha = (M-1)/2;n = -alpha:alpha;w = ones(1,M);omega = (2*pi/N)*[-N/2:N/2];Wr = real(w*(exp(-j*n'*omega)));db = 20*log10(abs(Wr)/max(Wr));IntWr = cumsum(Wr)/N;%% plotssubplot(2,2,3); plot(omega/pi,IntWr);axis([-1,1,-0.15,1.15]);title('M = 51')xlabel('frequency in pi units'); ylabel('Integrated Amplitude Response')set(gca,'YTickMode','manual','YTick',[0,1])set(gca,'XTickMode','manual','XTick',[-1,0,1]); grid%% M = 101M = 101; alpha = (M-1)/2;n = -alpha:alpha;w = ones(1,M);omega = (2*pi/N)*[-N/2:N/2];Wr = real(w*(exp(-j*n'*omega)));db = 20*log10(abs(Wr)/max(Wr));IntWr = cumsum(Wr)/N;%% plotssubplot(2,2,4); plot(omega/pi,IntWr);axis([-1,1,-0.15,1.15]);title('M = 101')xlabel('frequency in pi units'); ylabel('Integrated Amplitude Response')set(gca,'YTickMode','manual','YTick',[0,1])set(gca,'XTickMode','manual','XTick',[-1,0,1]); grid