clc;
clear;
close all;
n = 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));
endsubplot(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');