cosine static method
Returns a cosine window, such as Hanning or Hamming.
w[i] = 1 - amp - amp * cos(2πi / (size - 1))
Implementation
static Float64List cosine(int size, double amplitude) {
final offset = 1 - amplitude;
final scale = 2 * math.pi / (size - 1);
return _makeWindow(size, (i) => offset - amplitude * math.cos(scale * i));
}