Efficiently navigating a random Delaunay triangulation

Nicolas Broutin 1 Olivier Devillers 2, 3 Ross Hemsley 3
2 VEGAS - Effective Geometric Algorithms for Surfaces and Visibility
Inria Nancy - Grand Est, LORIA - ALGO - Department of Algorithms, Computation, Image and Geometry
3 GEOMETRICA - Geometric computing
CRISAM - Inria Sophia Antipolis - Méditerranée , Inria Saclay - Ile de France
Abstract : Planar graph navigation is an important problem with significant implications to both point location in geometric data structures and routing in networks. However, whilst a number of algorithms and existence proofs have been proposed, very little analysis is available for the properties of the paths generated and the computational resources required to generate them under a random distribution hypothesis for the input. In this paper we analyse a new deterministic planar navigation algorithm with constant competitiveness which follows vertex adjacencies in the Delaunay triangulation. We call this strategy \emph{cone walk}. We prove that given n uniform points in a smooth convex domain of unit area, and for any start point z and query point q; cone walk applied to z and q will access at most O(|zq| √n + log^7 n) sites with complexity O(|zq| √n log log n + log^7 n) with probability tending to 1 as n goes to infinity. We additionally show that in this model, cone walk is (log^(3+x) n)-memoryless with high probability for any pair of start and query point in the domain, for any positive x. We take special care throughout to ensure our bounds are valid even when the query points are arbitrarily close to the border.
Type de document :
Article dans une revue
Random Structures and Algorithms, Wiley, 2016, 49 (1), pp.95--136. <10.1002/rsa.20630>
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Contributeur : Olivier Devillers <>
Soumis le : lundi 11 avril 2016 - 14:40:00
Dernière modification le : vendredi 21 juillet 2017 - 11:12:43


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Nicolas Broutin, Olivier Devillers, Ross Hemsley. Efficiently navigating a random Delaunay triangulation. Random Structures and Algorithms, Wiley, 2016, 49 (1), pp.95--136. <10.1002/rsa.20630>. <hal-00940743v3>



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