The GeoDa Center for Geographical Analysis & Computation, led by ASU Regents' Professor Luc Anselin, has just released a new version of its signature software, OpenGeoDa. The software provides a user-friendly interface to implement techniques for exploratory spatial data analysis and spatial modeling. It has been used to better understand issues ranging from health care access to economic development to crime clusters. It is freely downloadable and open-source.
The software is used internationally, with more than 75,000 unique downloads, and lab installations at universities such as Harvard, MIT and Cornell. The new version, OpenGeoDa 1.2.0, provides the most significant enhancements since the first release in 2003.
A key addition in the new version is space-time analysis - maps and charts that make it possible to track changes in spatial patterns over time.
These two OpenGeoDa views allow exploration of a region's homicide patterns in both geographic and statistical space. The map (above) represents homicide rates for a cluster of counties, with high rates in red and low rates in blue. The parallel coordinate plot (below) allows for a visual and statistical assessment of how the counties' homicide rates (HR) relate to its police expenditures (PE) and resource deprivation (RDAC). Linking of the map with the graph allows the OpenGeoDa user to select a few counties (yellow) and see their values for all three variables on the plot (green). Changing the selection on the map will trigger a new selection on the plot, and vice versa, allowing for a comparison of subregions with the region as a whole.
The new version of OpenGeoDa can show how these relationships vary over time, and offers live links between the maps and different chart types such as scatter plots, histograms, box plots, parallel coordinate plots, 3D plots, conditional maps or plots, and bubble charts. Bubble charts are entirely new to OpenGeoDa and can visualize four variables by varying the size and color of scatterplot points.
OpenGeoDa runs on the National Center for Health Statistics' Research Data Center's servers; allowing researchers to use the software to analyze microdata not available elsewhere.
ASU's GeoDa Center for Geographical Analysis and Geocomputation, directed by Anselin, offers free downloads, documentation and tutorials to support new OpenGeoDa users.