question: protected void updateNumericScores ( double [ ] predicted , double [ ] actual , double weight ) { double diff ; double sumErr = 0 , sumAbsErr = 0 , sumSqrErr = 0 ; double sumPriorAbsErr = 0 , sumPriorSqrErr = 0 ; for ( int i = 0 ; i < m_NumClasses ; i ++ ) { diff = predicted [ i ] - actual [ i ] ; sumErr += diff ; sumAbsErr += Math . abs ( diff ) ; sumSqrErr += diff * diff ; diff = ( m_ClassPriors [ i ] / m_ClassPriorsSum ) - actual [ i ] ; sumPriorAbsErr += Math . abs ( diff ) ; sumPriorSqrErr += diff * diff ; } m_SumErr += weight * sumErr / m_NumClasses ; m_SumAbsErr += weight * sumAbsErr / m_NumClasses ; m_SumSqrErr += weight * sumSqrErr / m_NumClasses ; m_SumPriorAbsErr += weight * sumPriorAbsErr / m_NumClasses ; m_SumPriorSqrErr += weight * sumPriorSqrErr / m_NumClasses ; }
target:  Update the numeric accuracy measures. For numeric classes, the accuracy is between the actual and predicted class values. For nominal classes, the accuracy is between the actual and predicted class probabilities.