ArcView is chosen as the GIS environment in which traditional and spatial segregation measures were implemented. ArcView is chosen mainly because this GIS package probably has the largest user base in the GIS industry, and thus programs developed for ArcView can reach the most potential users. In no way choosing this package implies that the author endorses this package. Details regarding ArcView GIS can be found in the vendor's website (www.esri.com).
Programs developed to implement segregation indices
written in Avenue, a scripting language used by ArcView. Several Avenue
scripts were written to implement the 2-group D index and the
D(m) index. Several other scripts were written to implement the suite
spatial segregation indices (refer to the Background
and Literature section). All these scripts were incorporated into a
project file (.apr), which can be launched by clicking it. A customized
graphic-user interface (below) with additional menu items to access the
segregation measures is included. All the users need to do is to bring
in their data (with population attributes) as a theme in the shapefile
format, the native data format used by ArcView.
ArcView Project file and Graphic User Interface
* Recently (Jan 2005), a new menu item for computing local segregation indices has been added to the ArcView GUI. Please refer to the Background and Literature section for more information. Because a neighbor definition (in distance) has to be included, if 0 distance is used, only adjacent units will be included in the computing the local indices for areal unit i. The distance entered should be the mapping unit (e.g., miles or meters), which should be defined in the View Properties. But preferably the shapefiles are in coordinate systems/projections with less distortion on distance.
These local indices are functions of the neighborhood distance definition. The figure below shows that when the neighborhood distance definition increases (from immediate neighbors to 1 mile and then 2 miles), the local segregation levels will decrease in general.*