w = [-100:100]*pi/100; % frequency between -pi and +piN = 5;X1 = sin((w+eps)*N/2)./sin((w+eps)/2);N = 15;X2 = sin((w+eps)*N/2)./sin((w+eps)/2);N = 25;X3 = sin((w+eps)*N/2)./sin((w+eps)/2);N = 100;X4 = sin((w+eps)*N/2)./sin((w+eps)/2);subplot(1,1,1);subplot(2,2,1);plot(w/pi,X1);gridxlabel('frequency in pi units');title('N=5')subplot(2,2,2);plot(w/pi,X2);gridxlabel('frequency in pi units');title('N=15')subplot(2,2,3);plot(w/pi,X3);gridxlabel('frequency in pi units');title('N=25')subplot(2,2,4);plot(w/pi,X4);gridxlabel('frequency in pi units');title('N=100')