TODO:
frequency // int => working // float => not working
// should FT has sin() some shift periods build in? // FT missing shift of wave // center of mass has to be in the middle of X/Y axis
// normalize data into min === -1 & max === +1 and shift center of the mass into Y = 0
signal should have center mass in the zero to not to have init spikes!!!! sooo important!!!
// todo: study inverse fourier transform
test purely positive sin
použít mozek https://www.youtube.com/watch?v=spUNpyF58BY&t=19s&ab_channel=3Blue1Brown
derivative = 0 min max = -1 & +1
compute left/right shift of the final sins
float frequencies are not able to get by FT