Mathematical formulae used in Sonor

These are a few of the formulae used in Sonor.

FIR filter:

In Sonor, n=128, and a 20-coefficient FIR filter is calculated.

Resampling:

where <n> is the integer value of n.

FFT:

Sonor does not actually use FFT, it uses discrete cosine transform, or DCT for short, as it is more accurate:

s is a strength factor.

Add frequency:

s is the amplitude of the wave from 0.0 to 1.0. f is the frequency of the sample.