question: public double logDensityForInstance ( Instance instance ) throws Exception { double [ ] a = logJointDensitiesForInstance ( instance ) ; double max = a [ Utils . maxIndex ( a ) ] ; double sum = 0.0 ; for ( int i = 0 ; i < a . length ; i ++ ) { sum += Math . exp ( a [ i ] - max ) ; } return max + Math . log ( sum ) ; }
target:  Computes the density for a given instance.