Esempio n. 1
0
 private double getGiniIndex(ClassificationCounter cc) {
   double sum = 0.0d;
   for (Map.Entry<Serializable, Double> e : cc.getCounts().entrySet()) {
     double error = (cc.getTotal() > 0) ? e.getValue() / cc.getTotal() : 0;
     sum += error * error;
   }
   return 1.0d - sum;
 }
Esempio n. 2
0
 @Override
 public double scoreSplit(ClassificationCounter a, ClassificationCounter b) {
   ClassificationCounter parent = ClassificationCounter.merge(a, b);
   double parentGiniIndex = getGiniIndex(parent);
   double aGiniIndex = getGiniIndex(a) * a.getTotal() / parent.getTotal();
   double bGiniIndex = getGiniIndex(b) * b.getTotal() / parent.getTotal();
   return parentGiniIndex - aGiniIndex - bGiniIndex;
 }