The Math::FFT module provides an interface to various Fast Fourier Transform (FFT) routines of the C routine of fft4g.c, available at http://momonga.t.u-tokyo.ac.jp/~ooura/fft.html. The one-dimensional data sets, of size 2^n, are assumed to be sampled at a constant rate.

The FFT methods available are
- cdft: Complex Discrete Fourier Transform - rdft: Real Discrete Fourier Transform - ddct: Discrete Cosine Transform
- ddst: Discrete Sine Transform
- dfct: Cosine Transform of RDFT (Real Symmetric DFT) - dfst: Sine Transform of RDFT (Real Symmetric DFT) as well as their inverses.

Also available are some methods to implement some common applications of FFTs for real data sets. These are - correl: Find the correlation between two data sets - convlv: Find the convolution of one data set with another - deconvlv: Find the deconvolution of one data set with another - spctrm: Find the power spectrum of a data set, including application of a windowing function and segmentation of the data.

Finally, for convenience some common statistical methods are included for analyzing real data sets. These are - mean: Find the mean of a data set
- stdev: Find the standard deviation of a data set - range: Find the minimum and maximum values of a data set - median: Find the median of a data set - rms: Find the root mean square of a data set

The C code for the FFT routines of fft4g.c is copyrighted 1996-99 by Takuya OOURA. The file arrays.c included here to handle passing arrays to and from C comes from the PGPLOT module of Karl Glazebrook <kgb@aaoepp.aao.gov.au>. The perl interface of the Math::FTT module is Copyright 2000,2005 by Randy Kobes <r.kobes@uwinnipeg.ca>, and may be distributed under the same terms as Perl itself.