question: private double pdf ( double x , int j ) { int from = Arrays . binarySearch ( X , x - h * k . cutOff ( ) ) ; int to = Arrays . binarySearch ( X , x + h * k . cutOff ( ) ) ; from = from < 0 ? - from - 1 : from ; to = to < 0 ? - to - 1 : to ; if ( weights . length == 0 && k instanceof UniformKF ) return ( to - from ) * 0.5 / ( sumOFWeights * h ) ; double sum = 0 ; for ( int i = Math . max ( 0 , from ) ; i < Math . min ( X . length , to + 1 ) ; i ++ ) if ( i != j ) sum += k . k ( ( x - X [ i ] ) / h ) * getWeight ( i ) ; return sum / ( sumOFWeights * h ) ; }
target:  Computes the Leave One Out PDF of the estimator 