Computing largest empty circles with location constraints

Godfried Toussaint

    Research output: Contribution to journalArticle

    Abstract

    Let Q = {q1, q2,..., qn} be a set of n points on the plane. The largest empty circle (LEG) problem consists in finding the largest circle C with center in the convex hull of Q such that no point qi εQ lies in the interior of C. Shamos recently outlined an O(n log n) algorithm for solving this problem.(9) In this paper it is shown that this algorithm does not always work correctly. A different approach is proposed here and shown to also result in an O(n log n) algorithm. The new approach has the advantage that it can also solve more general problems. In particular, it is shown that if the center of C is constrained to lie in an arbitrary convex n-gon, an 0(n log n) algorithm can still be obtained. Finally, an 0(n log n +k log n) algorithm is given for solving this problem when the center of C is constrained to lie in an arbitrary simple n-gon P. where k denotes the number of intersections occurring between edges of P and edges of the Voronoi diagram of Q and k ≤O(n2).

    Original languageEnglish (US)
    Pages (from-to)347-358
    Number of pages12
    JournalInternational Journal of Computer & Information Sciences
    Volume12
    Issue number5
    DOIs
    StatePublished - Oct 1 1983

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    Circle
    Computing
    n-gon
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    Arbitrary
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    Interior
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    Keywords

    • algorithms
    • complexity
    • computational geometry
    • facility location
    • Largest empty circle
    • operations research
    • polygons
    • Voronoi diagram

    ASJC Scopus subject areas

    • Theoretical Computer Science
    • Computational Theory and Mathematics
    • Engineering(all)

    Cite this

    Computing largest empty circles with location constraints. / Toussaint, Godfried.

    In: International Journal of Computer & Information Sciences, Vol. 12, No. 5, 01.10.1983, p. 347-358.

    Research output: Contribution to journalArticle

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