摘要: While direction is fundamental to geography, the implementation of directionalfunctions in Geographical Information Systems (GIS) is limited. The focus paper is the extension of direction-related concepts through the definition of... 展开 While direction is fundamental to geography, the implementation of directionalfunctions in Geographical Information Systems (GIS) is limited. The focus paper is the extension of direction-related concepts through the definition of directional regions, such as the area north of Washington DC. Directional regions are constructed from combinations of six elements: the feature, the reference, an orientation, a viewspan, a viewfield and a region of interest. This approach allows users to create new area features which can be incorporated in a GIS. These features are a valuable tool for geographical analysis, since they further constrain reasoning on a data set.... Geographical analysis, Geographic Information Systems (GIS). 收起