X(k)=DFT[x(n)]= n=0 ∑ N−1 ​ x(n)e −j N 2π ​ nk , 0 ≤ k ≤ N − 1 0 \le k \le N-10≤k≤N−1 封装成matlab函数代码

function X = DFT(x)
% Computes the Discrete Fourier Transform of a signal x

N = length(x);
X = zeros(1,N);

for k = 0:N-1
for n = 0:N-1
X(k+1) = X(k+1) + x(n+1)*exp(-1j*2*pi*k*n/N);
end
end

end