The Space Package: Tight Integration between Space and Semantics

摘要

Interpretation of spatial features often requires combined reasoning over geometryand semantics. We introduce the Space package, an open source SWI-Prolog exten-sion that provides spatial indexing capabilities. Together with the existing semanticweb reasoning capabilities of SWI-Prolog, this allows efficient integration of spatialand semantic queries and provides an infrastructure for declarative programmingwith space and semantics. There are few systems that provide indexing and reason-ing facilities for both spatial and semantic data. A common solution is to combineseparate semantic reasoning and geospatial services. Such loose coupling has thedisadvantage that each service cannot make use of the statistics of the other. Thismakes optimization of such a service-oriented architecture hard. The SWI-PrologSpace and Semantic web packages provide a native Prolog interface to both spatialand semantic indexing and reasoning, which makes it easy to write combined queryoptimizers. Another advantage of the Space package is that it allows declarative logicprogramming, which means in practice that you say what you want to computeinstead of how to compute it. The actual indexing machinery is encapsulated insideProlog predicates. In this article we describe the interface of the Space package,compare its functionality to alternative software libraries, and show how to workwith it using three example applications. These example illustrations include rea-soning over movement patterns, dynamically loading geospatial linked data off thesemantic web, and setting up a simple KML server.