clear;
N=100;

for k = 1:N
    w(k) = 1*pi/N*k;
    H(k) = 1/3 * (1a+ exp(-j*w(k)) + exp(-j*2*w(k)));
    %H2(k) = 1/3 * (1+ exp(j*w(k)) + exp(j*2*w(k)))/exp(j*2*w(k));
    Habs(k) = (1+2*exp(-j*1.5*w(k))*cos(w(k)/2))/3;
    Pangle(k) = -1.5*j*w(k);
end

figure
subplot (2,2,1)
plot(w,abs(H))
grid on
title('Magnitude of Transfer function by Matlab');
xlabel('w');
ylabel('Magnitude');

subplot (2,2,2)
plot(w,angle(H))
grid on
title('Phase of Transfer function by Matlab');
xlabel('w');
ylabel('Phase');

subplot (2,2,3)
plot(w,Habs)
grid on
title('Magnitude of Transfer function by hand');
xlabel('w');
ylabel('Magnitude');

subplot (2,2,4)
plot(w,Pangle)
grid on
title('Phase of Transfer function by hand');
xlabel('w');
ylabel('Phase');