The VagueGeometry Abstract Data Type
Keywords:abstract data types, spatial databases, vague spatial objects, vague topological predicates
Spatial vagueness has been increasingly required by geoscientists to handle vague spatial objects, that is, spatial objects found in real-world phenomena that do not have exact locations, strict boundaries, or sharp interiors. However, there is a gap in the literature in how to handle spatial vagueness in spatial database management systems and Geographical Information Systems (GIS) since they mainly provide support to crisp spatial objects, that is, objects that have well-defined locations, boundaries, and interiors. In this article, we propose VagueGeometry, a novel abstract data type that allows users to manipulate vague spatial objects in spatial applications and GIS. The main advantages of our VagueGeometry are that (i) it offers textual and binary representations for vague spatial objects, (ii) it includes an expressive set of vague spatial operations, (iii) it supports SQL operators, and (iv) its implementation is open source. We also propose an improvement of VagueGeometry to deal efficiently with the processing of vague topological predicates. Experimental results show that VagueGeometry improved the performance of spatial queries with vague topological predicates from 21% up to 98% if compared with functionalities available in current spatial databases.