eFFT

The 'Easy Fast Fourier Transform' (eFFT) is a simple to use 1D radix-2 FFT library programmed in C. It was developed late 2015 / early 2016

Authors

T.Lloyd and S.Ismail

Background

The library was originally developed as a learning exercise to understand and implement the famous algorithm developed by Cooley and Tukey. Although many existing and faster implementations of the FFT exist, the authors wanted to develop their own version to better understand the algorithm and for use in projects. Further information about how the FFT works can be found in the bibliography at the bottom.

How To Use

The library contains two simple functions which are detailed below where the input is the data to under go transformation and length is the number of data points.

FFT

double complex * fft(double complex * input,int length);

IFFT

double complex * ifft(double complex * input,int length);

Bibliography

• [1] J. W. Cooley, J. W. Tukey. An Algorithm for the Machine Calculation of Complex Fourier Series. (1965) Math. Comput.
• [2] P. Gaydecki. Foundations of Digital Signal Processing: theory, algorithms and hardware design. (2004) IET Publishing.
• [3] J. Wu. Fast Fourier Transform(FFT). Available: http://www.cmlab.csie.ntu.edu.tw/cml/dsp/training/coding/transform/fft.html. (N/A)