Swiss canton regions: A model for complex objects in geographic partitions

Abstract

Spatial regions are a fundamental abstraction of geographic phenomena. While simple regions—disk-like and simply connected—prevail, in partitions complex configurations with holes and/or separations occur often as well. Swiss cantons are one highlighting example of these, bringing in addition variations of holes and separations with point contacts. This paper develops a formalism to construct topologically distinct configurations based on simple regions. Using an extension to the compound object model, this paper contributes a method for explicitly constructing a complex region, called a canton region, and also provides a mechanism to determine the corresponding complement of such a region.