StFFT
FFT on Structured text
Fast fourier transform algorithm written on IEC-61131-3 Structured text programming language for programmable logic controllers.
Algorithm is split-radix FFT. StFFT is iterative contrary to more common recursive approach. Iterative solution was chosen because PLCs don't have support for recursion. For compatibility with as many as possible PLC models, algorithm have dependency only on sine and cosine functions.
Dual licenced under LGPL and Commercial licence. For commercial licencing...