Point2Hex: Higher-order Mobility Flow Data and Resources

Ali Faraji, Jing Li, Gian Alix, Mahmoud Alsaeed, Nina Yanin, Amirhossein Nadiri, Manos Papagelis

Abstract: Research on trajectory data mining relies on appropriate datasets, including Gps-based geolocations, check-in data to points of interest (Pois), and synthetic datasets. Even though some data are accessible, the majority of mobility datasets are typically discovered through ad-hoc searches and lack comprehensive documentation of their generation process or source to reproduce curated or customized versions of them. At the same time, there has been a growing interest in a new type of mobility data, describing trajectories as sequences of higher-order geometric elements like hexagons that offer several benefits: (i) reduced sparsity and analysis at different granularity levels, (ii) compatibility with popular machine learning architectures, (iii) improved generalization and reduced overfitting, and (iv) efficient visualization. To this end, we present Point2Hex, a method and tool for generating higher-order mobility flow datasets from raw trajectory data. We used Point2Hex to create higherorder versions of seven popular mobility datasets typically employed in trajectory-related technical problems and downstream tasks, such as trajectory prediction, classification, clustering, imputation, and anomaly detection, to name a few. To promote reuse and encourage reproducibility, we provide the source code and documentation of Point2Hex, as well as the generated higher-order mobility flow datasets in publicly accessible repositories.