public double kurtosis(){
  double mu=mean();
  double devsum=0;
  double wsum=0;
  int size=values.size();
  for (int i=0; i < size; i++) {
    double dev=values.get(i) - mu;
    devsum+=Math.pow(dev,4.0d) * weights.get(i);
    wsum+=weights.get(i);
  }
  double mu4=devsum / wsum;
  double s4=Math.pow(variance(),4.0 / 2.0);
  return mu4 / s4;
}

public double kurtosis ( ) { double mu = mean ( ) ; double devsum = 0 ; double wsum = 0 ; int size = values . size ( ) ; for ( int i = 0 ; i < size ; i ++ ) { double dev = values . get ( i ) - mu ; devsum += Math . pow ( dev , 4.0d ) * weights . get ( i ) ; wsum += weights . get ( i ) ; } double mu4 = devsum / wsum ; double s4 = Math . pow ( variance ( ) , 4.0 / 2.0 ) ; return mu4 / s4 ; }
returns the ( weighted ) kurtosis ( not excess kurtosis ) of all samples .
