Shapefiles: Difference between revisions
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One of the most common methods for creating feature objects is to import a shapefile. The concept of a shapefile was established by [http://www.esri.com/ Environmental Systems Research Institute (ESRI)] in their ArcView® program and it has become the defacto standard for sharing GIS vector data (points, lines, and polygons). | One of the most common methods for creating feature objects is to import a shapefile. The concept of a shapefile was established by [http://www.esri.com/ Environmental Systems Research Institute (ESRI)] in their ArcView® program and it has become the defacto standard for sharing GIS vector data (points, lines, and polygons). | ||
A | A shapefile is actually comprised of three or more files. The primary file is the *.shp and it contains the geometric information (coordinates and if necessary connectivity of the points, lines, polygons). The *.dbf file is a standard database file and stores the attributes of the feature objects. Finally, there will be a *.shx file which is an indexing file. There may be a few other files that accompany the shapefile and so the user should always move them around together if copying or moving them to a new directory. | ||
Only one "theme" or type of feature can exist in a shapefile. For example the user cannot store points and polygons in the shapefile, or boundaries and so the user may be required to import multiple files. | Only one "theme" or type of feature can exist in a shapefile. For example the user cannot store points and polygons in the shapefile, or boundaries and so the user may be required to import multiple files. | ||
Revision as of 16:14, 8 August 2014
One of the most common methods for creating feature objects is to import a shapefile. The concept of a shapefile was established by Environmental Systems Research Institute (ESRI) in their ArcView® program and it has become the defacto standard for sharing GIS vector data (points, lines, and polygons).
A shapefile is actually comprised of three or more files. The primary file is the *.shp and it contains the geometric information (coordinates and if necessary connectivity of the points, lines, polygons). The *.dbf file is a standard database file and stores the attributes of the feature objects. Finally, there will be a *.shx file which is an indexing file. There may be a few other files that accompany the shapefile and so the user should always move them around together if copying or moving them to a new directory.
Only one "theme" or type of feature can exist in a shapefile. For example the user cannot store points and polygons in the shapefile, or boundaries and so the user may be required to import multiple files.
XMS software includes all of the tools necessary to import shapefiles and convert the geometric and attribute information into feature objects. This can be done by directly opening the shapefile and converting to feature objects in the active coverage or by loading the shapefile in the GIS module.
