MAPPING FROM A CARTOGRAPHIC EXTRACT

The Topologically Integrated Geographic Encoding and Referencing (TIGER) data base is the Census Bureau's primary source for map production. Collecting and chaining the TIGER data base's topological elements of 0-cells (points), 1-cells (lines), and 2-cells (areas) into meaningful cartographic objects is a major step in map creation. Rather than have each mapping application directly access the TIGER data base and independently perform the chaining process, the Census Bureau creates a secondary data base—a cartographic extract—from which mapping applications retrieve the coordinate strings of pre-chained cartographic objects. While developed initially to reduce overall computer processing requirements, the cartographic extract has additional implications for mapping applications, such as providing a conceptual framework for approaching the mapping task and enhancing the preproduction decision-making processes. © 1990 Taylor & Francis Group, LLC.