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A shape-"file" actually consisted of several files, including at the very least a .shp file to store the geometry, and a .dbf file for the attributes, the latter directly adopting the dBase format that was the dominant microcomputer database at the time (despite it being a proprietary trade secret, the .dbf format had been legally reverse ...
Spatial Data File – high-performance geodatabase format, native to MapGuide (by Autodesk) TIGER – Topologically Integrated Geographic Encoding and Referencing Vector Product Format – National Geospatial-Intelligence Agency (NGA)'s format of vectored data for large geographic databases
In each of the .shp, .shx, and .dbf files, the shapes in each file correspond to each other in sequence (i.e., the first record in the .shp file corresponds to the first record in the .shx and .dbf files, etc.). The .shp and .shx files have various fields with different endianness, so an implementer of the file formats must be very careful to ...
This was most common from the 1970s through the early 1990s, because GIS software developers had to invent their own geometry data structures, but incorporated existing relational database file formats for the attributes. For example, the Esri Shapefile format includes the .dbf file from the DOS dBase software.
GML defines features distinct from geometry objects. A feature is an application object that represents a physical entity, e.g. a building, a river, or a person. A feature may or may not have geometric aspects. A geometry object defines a location or region instead of a physical entity, and hence is different from a feature.
In this example from Soller and others (1999), [32] the upper surface of each buried geologic unit was represented in raster format as an ArcInfo Grid file. The middle grid is the uppermost surface of an economically important aquifer, the Mahomet Sand, which fills a pre- and inter-glacial valley carved into the bedrock surface.
In geographic information systems, a feature is an object that can have a geographic location and other properties. [1] Common types of geometries include points, arcs, and polygons. Carriageways and cadastres are examples of feature data. Features can be labeled when displayed on a map.
The ARC/INFO Coverage data structure (1981), a topological data model based on POLYVRT. Topology was a very early concern for GIS. The earliest vector systems, such as the Canadian Geographic Information System, did not manage topological relationships, and problems such as sliver polygons proliferated, especially in operations such as vector overlay. [9]