Summary: External­Memory Algorithms
for Processing Line Segments
in Geographic Information Systems
(extended abstract)
Lars Arge 1# , Darren Erik Vengro# 2## , and Je#rey Scott Vitter 3###
1 BRICS + , Department of Computer Science, University of Aarhus, Aarhus, Denmark
2 Department of Computer Science, Brown University, Providence, RI 02912, USA
3 Department of Computer Science, Duke University, Durham, NC 27708, USA
Abstract. In the design of algorithms for large­scale applications it is
essential to consider the problem of minimizing I/O communication. Ge­
ographical information systems (GIS) are good examples of such large­
scale applications as they frequently handle huge amounts of spatial data.
In this paper we develop e#cient new external­memory algorithms for
a number of important problems involving line segments in the plane,
including trapezoid decomposition, batched planar point location, trian­
gulation, red­blue line segment intersection reporting, and general line
segment intersection reporting. In GIS systems, the first three problems
are useful for rendering and modeling, and the latter two are frequently
used for overlaying maps and extracting information from them.
1 Introduction

Source: Arge, Lars - Department of Computer Science, Aarhus Universitet

Collections: Computer Technologies and Information Sciences