@Override public double variance(double totalWeight,double totalPositiveWeight,Hypothesis hypo){
  double fp=hypo.getCoveredWeight() - hypo.getPositiveWeight();
  double tn=totalWeight - totalPositiveWeight - fp;
  double correctPredictions=hypo.getPositiveWeight() + tn;
  double mean=correctPredictions / totalWeight;
  double innerTerm=correctPredictions * Math.pow(1.0d - mean,2) + (totalWeight - correctPredictions) * Math.pow(0.0d - mean,2);
  return Math.sqrt(innerTerm) / totalWeight;
}

@ Override public double variance ( double totalWeight , double totalPositiveWeight , Hypothesis hypo ) { double fp = hypo . getCoveredWeight ( ) - hypo . getPositiveWeight ( ) ; double tn = totalWeight - totalPositiveWeight - fp ; double correctPredictions = hypo . getPositiveWeight ( ) + tn ; double mean = correctPredictions / totalWeight ; double innerTerm = correctPredictions * Math . pow ( 1.0d - mean , 2 ) + ( totalWeight - correctPredictions ) * Math . pow ( 0.0d - mean , 2 ) ; return Math . sqrt ( innerTerm ) / totalWeight ; }
calculates the empirical variance .
