s'authentifier
version française rss feed
inria-00404171, version 1
Voir la fiche détaillée  BibTeX  EndNote  TEI  RefWorks
Helly-type theorems for approximate covering
Julien Demouth () 1, Olivier Devillers (, http://www-sop.inria.fr/geometrica/team/Olivier.Devillers/) 2, Marc Glisse () 3, Xavier Goaoc (, http://www.loria.fr/~goaoc) 1
(2009)
Icone de appcover.pdf
Discrete & Computational Geometry 42, 3 (2009) 379--398
Let F ∪ {U } be a collection of convex sets in Rd such that F covers U . We prove that if the elements of F and U have comparable size then a small subset of F suffices to cover most of the volume of U ; we analyze how small this subset can be depending on the geometry of the elements of F , and show that smooth convex sets and axis parallel squares behave differently. We obtain similar results for surface-to-surface visibility amongst balls in 3 dimensions for a notion of volume related to form factor. For each of these situations, we give an algorithm that takes F and U as input and computes in time O (|F | ∗ |Hϵ |) either a point in U not covered by or a subset ϵ covering U up to a measure ϵ, with ϵ meeting our combinatorial bounds.
1 :  VEGAS (INRIA Lorraine - LORIA)
INRIA – CNRS : UMR7503 – Université Henri Poincaré - Nancy I – Université Nancy II – Institut National Polytechnique de Lorraine
2 :  GEOMETRICA (INRIA Sophia Antipolis / INRIA Saclay - Ile de France)
INRIA
3 :  Grenoble Images Parole Signal Automatique (GIPSA-lab)
CNRS : UMR5216 – Université Joseph Fourier - Grenoble I – Université Pierre Mendès-France - Grenoble II – Université Stendhal - Grenoble III – Institut Polytechnique de Grenoble
Informatique/Géométrie algorithmique
10.1007/s00454-009-9167-1