skewness function

double? skewness(List<double> data)

Computes the skewness of a distribution.

Implementation

double? skewness(List<double> data) {
  if (data.length < 3) return null;

  final n = data.length;

  double sum = 0;
  for (final x in data) {
    sum += x;
  }
  final mean = sum / n;

  double m2 = 0, m3 = 0;
  for (final x in data) {
    final d = x - mean;
    m2 += d * d;
    m3 += d * d * d;
  }
  m2 /= n;
  m3 /= n;

  if (m2 == 0) return null;

  return m3 / math.pow(m2, 1.5);
}