n = input('Enter number of data points: ');
t = (2*pi/n)*(0:(n-1));
x = 1 + cos(t) + 2*sin(2*t); %Create a simple signal
z = fft(x); %fft is the fast Fourier transform algorithm
%Note that if n is odd z(n) is the complex conjugate of z(2),
%z(n-1) is the complex conjugate of z(3), etc.
m = (n-1)/2;
a = real(2*z(1:m+1)/n); %Recover frequency content of signal.
b = -imag(2*z(2:m+1)/n);