Choropleth maps are a widely used form of thematic mapping in which geographic areas are shaded using graduated colors to represent numeric values. Each area—typically a census unit or administrative ...
John Gerth, of the computer science department at Stanford, sent a link to a powerful illustration, by Latoya Egwuekwe, of the spreading effects of unemployment across the country during this ...
Geographic Information Systems (GIS) is specialist software that links geographical data with a map. Geographic Information Systems (GIS) enables users to add layers to show different information and ...
The map areas use the default pattern, which is a solid fill that rotates through the colors list. Because the colors list is specified in the GOPTIONS statement, all colors are used in the rotation.