Planar point location for large data sets

Abstract

We present an algorithm for external memory planar point location that is both effective and easy to implement. The base algorithm is an external memory variant of the bucket method by Edahiro, Kokubo and Asano that is combined with Lee and Yang's batched internal memory algorithm for planar point location. Although our algorithm is not optimal in terms of its worst-case behavior, we show its efficiency for both batched and single-shot queries by experiments with real-world data. The experiments show that the algorithm benefits from the mainly sequential disk access pattern and significantly outperforms the fastest algorithm for internal memory. Due to its simple concept, the algorithm can take advantage of multiple disks and processors in a rather straightforward yet efficient way.