RecMap: Rectangular Map Approximations

In many application domains, data is collected and referenced by its geo-spatial location. Nowadays, different kinds of maps are used to emphasize the spatial distribution of one or more geo-spatial attributes. The nature of geo-spatial statistical data is the highly non-uniform distribution in the real world data sets. This has several impacts on the resulting map visualizations. Classical area maps tend to highlight patterns in large areas, which may, however, be of low importance. Cartographers and geographers used cartograms or value-by-area maps to address this problem long before computers were available. Although many automatic techniques have been developed, most of the value-by-area cartograms are generated manually via human interaction. In this paper, we propose a novel visualization technique for geo-spatial data sets called RecMap. Our technique approximates a rectangular partition of the (rectangular) display area into a number of map regions preserving important geo-spatial constraints. It is a fully automatic technique with explicit user control over all exploration constraints within the exploration process. Experiments show that our technique produces visualizations of geo-spatial data sets, which enhance the discovery of global and local correlations, and demonstrate its performance in a variety of applications.