Axis maps blog is sharing an interesting technique for adding another dimension of data to maps by using transparency.  Somewhat like a cartogram, they’ve taken each county in the US and modified it based on population density, but instead of stretching it to a new size, they’ve increased the alpha transparency to make more populated areas brighter and less populated areas faded out. (more…)

One of the most challenging types of data to convert into a chart or visualization is also one of the most common: Multi-Level or ‘Hierarchical’ data.

Perhaps every category of data is composed of sub-categories, or a change in one data point has a major effect on surrounding data, but regardless, the standard library of charts and graphs doesn’t offer much in the way of making hierarchical data clear, so here are a few alternatives: (more…)

A Standard 2008 Election Map (Upper), and a Cartogram skewed by Population (Lower)

Cartograms, or visualizations of an area skewed by some variable, are a powerful tool to control for disparities over a large area, especially with respect to politics.

A relatively large but sparsely populated area will dominate a standard projection, whereas a cartogram allows populated areas to be warped to show their true influence (See sidebar).

Applications of Cartograms:

Socio-economic data is the most obvious use case for cartograms, particularly data from the United Nations and National Elections.

(more…)