%
%  Inverse Discrete Fourier Transform
%
function x = idft(Xk)
[N,M] = size(Xk);
if M ~=1,   % makes sure that Xk is a column vector
  Xk = Xk.';
  N = M;
end
x=zeros(N,1);
k = 0:N-1;
for n=0:N-1
  x(n+1) = exp(j*2*pi*k*n/N)*Xk;
end
x = x/N;