question: public double patience ( int k , F f , int N ) { double pf = p ( f ) ; BinomialDistribution dist = new BinomialDistribution ( null , N , pf ) ; double p0 = Math . pow ( 1 - pf , N ) ; return 1 - ( dist . cumulativeProbability ( k - 1 ) - p0 ) / ( 1 - p0 ) ; }
target:  Return the patience, i.e., the penalization of having a number of items with the same feature in a recommendation list of a given size.