function myFFT = ass5e2()
%% n = 500
n = 500;
t = linspace(0,1000,n);
x = sin(80*pi*t) + 0.5*sin(180*pi*t);
% x = [1 0 -1 0];
w = exp(-2*i*pi/n);
wmat = ones(n,n);

for a = (1:n)
    for b = (1:n)
        wmat(a,b) = w^(mod((a-1)*(b-1),n));
    end
end
wmat = (1/sqrt(n)) * wmat;
x = x';
z = wmat*x;
hold on
xlabel('Frequencies (Hz)');
ylabel('Amplitude');
plot([0:2:1000-2],abs(z))
z(2:11)
z(n-9:n)
end