English

A generalization of crossing families

Computational Geometry 2017-02-27 v1

Abstract

For a set of points in the plane, a \emph{crossing family} is a set of line segments, each joining two of the points, such that any two line segments cross. We investigate the following generalization of crossing families: a \emph{spoke set} is a set of lines drawn through a point set such that each unbounded region of the induced line arrangement contains at least one point of the point set. We show that every point set has a spoke set of size n8\sqrt{\frac{n}{8}}. We also characterize the matchings obtained by selecting exactly one point in each unbounded region and connecting every such point to the point in the antipodal unbounded region.

Keywords

Cite

@article{arxiv.1702.07555,
  title  = {A generalization of crossing families},
  author = {Patrick Schnider},
  journal= {arXiv preprint arXiv:1702.07555},
  year   = {2017}
}

Comments

14 pages, 10 figures