Formalizing Importance: Parameters for Settlement Selection from a Geographic Database

Doug Flewelling and Max Egenhofer

Abstract

This paper describes a model for selecting features from a geographic database to be displayed on a computer generated map display. An engineering approach is used to generate a set of geographic features similar to what would be chosen by a human, without attempting to replicate the human selection process. Selection is a process of choosing from a set of objects according to some ordering scheme. Humans have a highly developed ability to order sets of things. The model presented capitalizes on this ability by relying on user-defined ordering functions to produce an ordered set (ranked list) of geographic features. It is possible to process systematically the ranked list such that measurable qualities of the set such as subset relationships, pattern, dispersion, density, or importance are preserved. The resulting set of candidate features is placed on the map display using accepted generalization techniques.