Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Living with lrs School of Computer Science

Summary: Living with lrs
David Avis
School of Computer Science
McGill University
3480 University, Montreal, Quebec, Canada H3A 2A7
This paper describes the development of lrs, an implementation of
the reverse search method to the vertex enumeration/convex hull prob≠
lem for convex polyhedra. We describe an important and difficult class
of polyhedra, called configuration polytopes, that have application to
determining the ground states of alloy phase diagrams. Experience
gained while trying to solve these problems lead to a number of
improvements to the original implementation.
1. Introduction
A classic result is that a convex polyhedron P can be represented in two ways.
An H≠representation is given by an m ◊ d matrix A = (a i, j ) and m≠vector b = (b i ):
P = {yőR d | b + Ay ≥ 0}. (1)
We assume throughout that P is full dimensional and has at least one vertex, which
implies that m ≥ d . If A is minimal, that is no row can be deleted without changing P,


Source: Avis, David - School of Computer Science, McGill University


Collections: Computer Technologies and Information Sciences