hide
Free keywords:
Computer Science, Computational Geometry, cs.CG
Abstract:
This paper describes an implementation of fast near-neighbours queries (also
known as range searching) with respect to the Fr\'echet distance. The algorithm
is designed to be efficient on practical data such as GPS trajectories. Our
approach is to use a quadtree data structure to enumerate all curves in the
database that have similar start and endpoints as the query curve. On these
curves we run positive and negative filters to narrow the set of potential
results. Only for those trajectories where these heuristics fail, we compute
the Fr\'echet distance exactly, by running a novel recursive variant of the
classic free-space diagram algorithm.
Our implementation won the ACM SIGSPATIAL GIS Cup 2017.
