![]() ![]() ![]() |
![]() |
|
|
![]() ![]() ![]() ![]() ![]() |
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Return to Geographic Data Modeling From the point of view of mapping transformation, this paper presents a map generalization conceptual framework which regards generalization as two kinds of mapping procedures: spatial entity mapping and spatial relationship mapping. According to the number of changes in the participating entities, spatial entity mapping is classified as 1-1, n-1, n-m mapping. Spatial relationship mapping is described as a composite relationship transformation of the components: topology, distance and orientation. The concept 'spatial relationship resolution' is introduced to describe spatial relationship related constraints. Based on the 9 intersection model, the cardinal direction model and the iso-distance-relationship model, the paper gives three sorts of relationship resolution representations for topological, distance and orientation relationship respectively. The behavior of the two mappings in map generalization is discussed and the spatial relationship abstraction obtains emphasis compared with the traditional generalization conceptual model. ![]() DiSC'02 © 2003 Association for Computing Machinery |