Many scripts requiers symbolic package (octave-symbolic)
DFT - discrette fourier transform
FFT - fast fourier transform
fold - folding of two vectors ("свёртка")
transit_char - evaluate counts of transitional characteristics
impulse_char - evaluate counts of impulse characteristics
integrate_determinated - use quad approx to evaluate integral
integrate_determinated - get integral of symbolic function (for 1, 2 and 3 variables)
mathexp_discrete - get mathematical expectation of discrete set random value