On the Average Number of Edges in Theta Graphs

Theta graphs are important geometric graphs that have many applications, including wireless networking, motion planning, real-time animation, and minimum-spanning tree construction. We give closed form expressions for the average degree of theta graphs of a homogeneous Poisson point process over the plane. We then show that essentially the same bounds---with vanishing error terms---hold for theta graphs of finite sets of points that are uniformly distributed in a square. Finally, we show that the number of edges in a theta graph of points uniformly distributed in a square is concentrated around its expected value.

[1]  L. K. Jones,et al.  Strong Connectivity in Directional Nearest-Neighbor Graphs , 1981 .

[2]  Andrew Chi-Chih Yao,et al.  On Constructing Minimum Spanning Trees in k-Dimensional Spaces and Related Problems , 1977, SIAM J. Comput..

[3]  T. Asano,et al.  Approximation Algorithms for Shortest Path Motion Planning (Extended Abstract) , 1987 .

[4]  L. Devroye THE EXPECTED SIZE OF SOME GRAPHS IN COMPUTATIONAL GEOMETRY , 1988 .

[5]  J. Mark Keil,et al.  Approximating the Complete Euclidean Graph , 1988, Scandinavian Workshop on Algorithm Theory.

[6]  Colin McDiarmid,et al.  Surveys in Combinatorics, 1989: On the method of bounded differences , 1989 .

[7]  David Eppstein,et al.  The expected extremes in a Delaunay triangulation , 1991, Int. J. Comput. Geom. Appl..

[8]  Carl Gutwin,et al.  Classes of graphs which approximate the complete euclidean graph , 1992, Discret. Comput. Geom..

[9]  Daryl J. Daley,et al.  An Introduction to the Theory of Point Processes , 2013 .

[10]  Tamás Lukovszki,et al.  Geometric Searching in Walkthrough Animations with Weak Spanners in Real Time , 1998, ESA.

[11]  Luc Devroye,et al.  Unoriented Theta-Maxima in the Plane: Complexity and Algorithms , 1998, SIAM J. Comput..

[12]  J. Yukich,et al.  Central limit theorems for some graphs in computational geometry , 2001 .

[13]  J. Dall,et al.  Random geometric graphs. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[14]  Xiang-Yang Li,et al.  Geometric spanners for wireless ad hoc networks , 2002, Proceedings 22nd International Conference on Distributed Computing Systems.

[15]  J. Yukich,et al.  Weak laws of large numbers in geometric probability , 2003 .

[16]  Gábor Lugosi,et al.  Concentration Inequalities , 2008, COLT.

[17]  Joachim Gudmundsson,et al.  On the expected maximum degree of Gabriel and Yao graphs , 2009, Advances in Applied Probability.

[18]  Nicolas Bonichon,et al.  Connections between Theta-Graphs, Delaunay Triangulations, and Orthogonal Surfaces , 2010, WG.

[19]  Esther M. Arkin,et al.  Probabilistic Bounds on the Length of a Longest Edge in Delaunay Graphs of Random Points in d-Dimensions , 2011, CCCG.

[20]  Prosenjit Bose,et al.  The theta-5-graph is a spanner , 2012, ArXiv.

[21]  Prosenjit Bose,et al.  On the Stretch Factor of the Theta-4 Graph , 2013, WADS.

[22]  Prosenjit Bose,et al.  The θ5-graph is a spanner , 2015, Comput. Geom..

[23]  Ulrike Goldschmidt,et al.  An Introduction To The Theory Of Point Processes , 2016 .

[24]  Thorsten Gerber,et al.  Handbook Of Mathematical Functions , 2016 .