Efficient Algorithms for Detecting Regular Point Configurations

  • Luzi Anderegg
  • Mark Cieliebak
  • Giuseppe Prencipe
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3701)


A set of n points in the plane is in equiangular configuration if there exist a center and an ordering of the points such that the angle of each two adjacent points w.r.t. the center is \(\frac{360^{\circ}}{n}\), i.e., if all angles between adjacent points are equal. We show that there is at most one center of equiangularity, and we give a linear time algorithm that decides whether a given point set is in equiangular configuration, and if so, the algorithm outputs the center. A generalization of equiangularity is σ-angularity, where we are given a string σ of n angles and we ask for a center such that the sequence of angles between adjacent points is σ. We show that σ-angular configurations can be detected in time O(n 4 log n).


Weber point equiangularity σ-angularity design of algorithms computational geometry 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Luzi Anderegg
    • 1
  • Mark Cieliebak
    • 1
  • Giuseppe Prencipe
    • 2
  1. 1.ETH Zurich 
  2. 2.Università di Pisa 

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