% Program P10_4% Effect of Down-sampling in the Frequency Domain% Use fir2 to create a bandlimited input sequenceclf;freq = [0 0.42 0.48 1]; mag = [0 1 0 0];x = fir2(101, freq, mag);% Evaluate and plot the input spectrum[Xz, w] = freqz(x, 1, 512);subplot(2,1,1);plot(w/pi, abs(Xz)); gridxlabel('\omega/