The Math::FFT module provides an interface to various Fast Fourier Transform (FFT) routines of the C routine of fft4g.c; 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. 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 . The perl interface of the Math::FTT module is Copyright 2000 by Randy Kobes , and may be distributed under the same terms as Perl itself. WWW: http://search.cpan.org/dist/Math-FFT/