On Wed, 06 Jul 2011 22:05:52 +0200, Christian Heimes wrote: > On the other hand FFT are based on e, complex numbers or > trigonometric functions (=floats), which mean you'll get rounding errors. It's possible to perform a DFT over any field. Schoenhage-Strassen uses a DFT over a finite field (integers modulo N); it doesn't use floats.