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Two Matlab Functions for Understanding How Fast Fourier Transform Works

version (805 KB) by Zhigang Xu
Two m-functions, sfft and sifft, are supplied as plain text counterparts to the Matlab binary built-


Updated 10 Feb 2014

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Matlab has fft and ifft already to fast calculate discrete Fourier transform and its inverse. However they are binary built-in functions, hence their codes are not visible, which is not helpful to someones who want to understand how FFT works. For teaching and learning purposes, I think we should also have a pair of their readable counterparts, written and stored in plain text (the so-called the Matlab m-functions), which we can step through during their executions. I searched Mathworks file exchange center but did not find any one had contributed such m-functions. Therefore I hope that the m-functions that I am going to contribute will be welcome to the Matlab user community.

To avoid name conflicting, I name my pair of functions sfft and sifft. Using letter s as a prefix is learnt from Professor Gilbert Strang in MIT, who presented slu as readable counterpart to the Matlab built-in function lu for lower and upper triangular matrix factorization I do not know why he chose s at the first place. Perhaps it was derived from the word script, something written in text.

Cite As

Zhigang Xu (2020). Two Matlab Functions for Understanding How Fast Fourier Transform Works (, MATLAB Central File Exchange. Retrieved .

Comments and Ratings (2)

Benjamin Brenner

nipawan pakoktom


Typos in the document are corrected.

Corrected a typo in the description.

MATLAB Release Compatibility
Created with R2013a
Compatible with any release
Platform Compatibility
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