double SymmetricUncertaintyCalculator::calculateScore(const DataFrame& df1, int factorIndex1, 
   const DataFrame& df2, int factorIndex2) 
 { 
   return calculateUncertainty(df1, factorIndex1, df2, factorIndex2); 
 }
 double InformationGainCalculator::calculateScore(const DataFrame& df1, int factorIndex1, 
   const DataFrame& df2, int factorIndex2) 
 { 
   return calculateUncertainty(df1, factorIndex1, df2, factorIndex2); 
 }