SignalUtils

Calculates the Discrete Fourier transformation (DFT) for an array of frequencies defined in the Freq parameter. Goertz returns the DFT of the frequencies pass as a parameter in the Dst variable. Each value of the DFT computed by the Goertzel algorithm takes 2N+2 real multiplications and 4N real additions. FFT computes the DFT with N*log2(N) of real multiplications and additions. 

The Goertz method is faster, than direct DFT, if we need values at consecutively different frequencies. If at every call the values in Freq parameter are different. If the frequencies, at which we need to evalute the spectrum are fixed between calls, then the direct DFT method is faster.

Goertz

Functions