Solving Large-Scale Minimum-Weight Triangulation Instances to Provable Optimality

TL;DR

This paper presents advanced algorithms and parallel computing techniques that enable the exact solution of large-scale minimum-weight triangulation problems with up to 30 million points, surpassing previous size limitations.

Contribution

The authors extend and refine existing heuristics with new modifications and parallelization, allowing provably optimal solutions for much larger and diverse MWT instances.

Findings

Solved MWT instances with up to 30 million points in under 4 minutes.

Successfully computed optimal solutions for various benchmark datasets including TSPLIB and VLSI instances.

Demonstrated practical feasibility of solving large MWT problems despite their NP-hardness.

Abstract

We consider practical methods for the problem of finding a minimum-weight triangulation (MWT) of a planar point set, a classic problem of computational geometry with many applications. While Mulzer and Rote proved in 2006 that computing an MWT is NP-hard, Beirouti and Snoeyink showed in 1998 that computing provably optimal solutions for MWT instances of up to 80,000 uniformly distributed points is possible, making use of clever heuristics that are based on geometric insights. We show that these techniques can be refined and extended to instances of much bigger size and different type, based on an array of modifications and parallelizations in combination with more efficient geometric encodings and data structures. As a result, we are able to solve MWT instances with up to 30,000,000 uniformly distributed points in less than 4 minutes to provable optimality. Moreover, we can compute optimal solutions for a vast array of other benchmark instances that are not uniformly distributed, including normally distributed instances (up to 30,000,000 points), all point sets in the TSPLIB (up to 85,900 points), and VLSI instances with up to 744,710 points. This demonstrates that from a practical point of view, MWT instances can be handled quite well, despite their theoretical difficulty.