2014/12/16 by Pablo Pérez-Lantero, Pérez-Lantero, Pablo
Computer Science · #Computational Geometry (cs.CG) #FOS: Computer and information sciences #cs.CG
paper · pdf · doi:10.48550/arxiv.1412.5153
arxiv created 2015/09/09 · arxiv updated 2015/09/10
Given a set P of n points in the plane, we study the computation of the probability distribution function of both the area and perimeter of the convex hull of a random subset S of P. The random subset S is formed by drawing each point p of P independently with a given rational probability πp. For both measures of the convex hull, we show that it is #P-hard to compute the probability that the measure is at least a given bound w. For ε∈(0,1), we provide an algorithm that runs in O(n6/ε) time and returns a value that is between the probability that the area is at least w, and the probability that the area is at least (1-ε)w. For the perimeter, we show a similar algorithm running in O(n6/ε) time. Finally, given ε,δ∈(0,1) and for any measure, we show an O(nlog n+ (n/ε2)log(1/δ))-time Monte Carlo algorithm that returns a value that, with probability of success at least 1-δ, differs at most ε from the probability that the measure is at least w.