You do not have access to the code for MATLAB's FFT. If you remove the MATLAB specific wrapper functions, it uses the FFTW library under the hood (http://www.fftw.org/
). MATLAB does provide a function that allows tune the runtime speed of fft. Type 'help fftw' or 'doc fftw' at the MATLAB command prompt.I have never used the fftw function, so I don't know if it will help or suggestions for options/usage.