Variables: To define how you want to visualize your data (spatially, and in charts), variables specify the combination of data you want to understand. Each variable needs at minimum a name, data table, column name, and binning strategy. If you want, you can normalize variables by dividing a numerator and denominator data column in each geography, such as GDP per capita. Variables can also handle time-series data, where you can define a date index rather than a specific column name.
Variables are used for both map representations, where each polygon is colored based on the value of the data, and in chart or information representations -- currently supported are distribution graphs of Histograms, 2D Scatterplots, and Scaled Dot 2D Histogram, and Heatmap. WebGeoDa will automatically populate the spatial scales that have the correct tables. WebGeoDa will also automatically swap to the relevant data set when changing variables, if the current geographic scale doesn't have the data needed.