function X = dftm( N )

% generates a NxN DFT matrix
%
%   dftm( N ) : the above

% our return value
X = zeros(N,N);

% generate matrix
for k = 1 : N
    for n = 1 : N
        X(k,n) = exp(-j*2*pi*(k-1)*(n-1)/N);
    end
end