BIT Numerical Mathematics

, Volume 23, Issue 4, pp 456–471

On the X-Y convex hull of a set of X-Y polygons

Authors

  • T. M. Nicholl
    • Department of Electrical Engineering and Computer ScienceNorthwestern University
  • D. T. Lee
    • Department of Electrical Engineering and Computer ScienceNorthwestern University
  • Y. Z. Liao
    • IBM T. J. Watson Research Center
  • C. K. Wong
    • IBM T. J. Watson Research Center
Part I Computer Science

DOI: 10.1007/BF01933620

Cite this article as:
Nicholl, T.M., Lee, D.T., Liao, Y.Z. et al. BIT (1983) 23: 456. doi:10.1007/BF01933620

Abstract

We study the class of rectilinear polygons, calledX – Y polygons, with horizontal and vertical edges, which are frequently used as building blocks for very large-scale integrated (VLSI) circuit layout and wiring. In the paper we introduce the notion of convexity within the class ofX – Y polygons and present efficient algorithms for computing theX – Y convex hulls of anX – Y polygon and of a set ofX – Y polygons under various conditions. Unlike convex hulls in the Euclidean plane, theX – Y convex hull of a set ofX – Y polygons may not exist. The condition under which theX – Y convex hull exists is given and an algorithm for testing if the given set ofX – Y polygons satisfies the condition is also presented.

Keywords

Analysis of algorithmsconvexityrectilinear polygons

Copyright information

© BIT Foundations 1983