clc;
  clear;
  close all;
  n = 0:20;
  x=sin(0.2*pi*n);
  w= -pi:0.01:pi;
  X=zeros(size(w));
  for k= 1:length(w)
  X(k)= sum(x.*exp(-1j*w(k)*n));
  end 
  subplot(2,1,1);
  plot(w/pi,abs(X));
  grid on;
  title('Magnitude Spectrum of Signal');
  xlabel('Normalized Frequency');
  ylabel('|X(e^{j\omega})|');
  subplot(2,1,2);
  plot(w/pi,angle(X));
  grid on;
  title('Phase Spectrum of Signal');
  xlabel('Normalized Frequency');
  ylabel('Phase');