A bivariate choropleth map represents areal data from observations with two variables each instead of just one (univariate). This map of the United States is bivariate because the study monitored observations with two variables: people per square mile in 1990 and the percent change in population from then to 2000. This allows the reader to compare the population for the two years as well as understand the trend of the population change.
No comments:
Post a Comment