How can I get the code for MATLAB's FFT and CZT functions?

I'm looking to dig around inside of the FFT and Chirp Z-Transform CZT functions to see how performance is impacted by changing the bit depths at various points in the computation. My goal is to arrive at a more efficient FPGA implementation for my unique operating conditions. I would like to start with the code for these functions, which is somewhere inside of MATLAB, instead of writing the code directly from math papers. Unfortunately, when I use "edit fft" I get nothing but a large comment block ending in "Built-in function." How do I get the code out of these functions so I can alter and optimize it?

To be clear, I don't care about assigning these new functions to be used by default by MATLAB or superceding or alterning the built in functions themselves, I just want to make a copy to work with.

Thank you.

Answer 1

[Sreelakshmi S.B]

Typing 'edit czt' will give you the source code for the czt function in MATLAB. In the case of FFT, MATLAB uses the FFTW library,for which the source is freely available online.