Operatoren Error sum?

[dreckKopf]

Was berechnet das?

    private static double calc(double... ds) {
    double squaredErrorSum = 0.0;
    double weightSum = 0.0;
    int valueCount = ds.length;

    for (int t = 0; t < valueCount; t++) {
      double error = ds[t];
      double weight = t + 1.0;
      squaredErrorSum += weight * error * error;
      weightSum += weight;
    }
    return squaredErrorSum / weightSum;
  }