mfft

This short bit of code is a full fledged radix-2 fast fourier transform.
It is kept short and easy to read to make it easy for students to learn and understand the fast fourier algorithm.
As this algorithm is recursive, it does not require the butterfly reordering of input or output data.
Length of the input must be a power of 2.

SYNTAX:
y = mfft(1:2^10)

EXAMPLE:
n = 2^10;
data = sind((1:n)*10)'+rand(n,1);
y = mfft(data);

subplot(2,1,1);
plot(data);
xlim([1 n]);
subplot(2,1,2);
plot(abs(y));
xlim([1 n]);