An iconic query language for topological relationships in GIS |
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| Authors: | Y C Lee F L Chin |
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| Institution: | 1. Department of Geodesy and Geomatics , University of New Brunswick , Fredericton, N.B., Canada E3B 5A3;2. Universal Systems Limited , P.O. Box 3391, Station B Fredericton, N.B., Canada |
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| Abstract: | Abstract The study of query languages for spatial databases is an active research area. This paper describes a new spatial query language that uses a visual grammar to express topological relationships. It is supplemented by text and icons to handle other spatial and non-spatial queries. A graphical user interface is also developed to provide an interactive environment for composing the iconic query command. To test the language, the interface is implemented on a SUN 4 Workstation and linked to Ingres, a relational DBMS. Preliminary tests show that the iconic query language is more convenient for expressing spatial concepts than conventional textual languages. This is due mainly to the two-dimensionality of iconic languages in contrast with the linear nature of conventional languages. |
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| Keywords: | stereographic projection (SP) intersection predicate 3D GIS analysis models point inclusion line traversing |
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