Towards Measuring Place Function Similarity at Fine Spatial Granularity with Trajectory Embedding

TL;DR

This paper investigates the use of trajectory embedding to measure place function similarity at fine spatial scales, confirming its effectiveness while highlighting the influence of local geographical distance.

Contribution

It extends trajectory embedding-based place function similarity measurement to finer spatial granularity and examines the impact of geographical distance on this similarity.

Findings

Embedding similarity correlates with place functions at small scales.

Geographical distance influences embedding similarity.

Trajectory embedding is a valid metric proxy for place functions.

Abstract

Modeling place functions from a computational perspective is a prevalent research topic. Trajectory embedding, as a neural-network-backed dimension reduction technology, allows the possibility to put places with similar social functions at close locations in the embedding space if the places share similar chronological context as part of a trajectory. The embedding similarity was previously proposed as a new metric for measuring the similarity of place functions. This study explores if this approach is meaningful for geographical units at a much smaller geographical granularity compared to previous studies. In addition, this study investigates if the geographical distance can influence the embedding similarity. The empirical evaluations based on a big vehicle trajectory data set confirm that the embedding similarity can be a metric proxy for place functions. However, the results also show that the embedding similarity is still bounded by the distance at the local scale.