Radial Treemaps

By: Jeff Clark    Date: Tue, 11 Apr 2006

In the previous post I briefly described an application based on a type of visualization called a Treemap. They are definitely a useful technique in the right context but after exploring them a bit I found the generated images a bit unsatisfying. The things that I dislike about them are:

  1. the irregularity of the layout
  2. the hierarchies are not clearly expressed
  3. it's difficult to illustrate multi-level hierarchies

Problems 2 & 3 are nicely addressed by a variation which Kai Wetzel calls a Circular Treemap. This design has the obvious drawback that the visualization is no longer space-filling - you can't fit as much information into the same area as with the standard rectangular treemap.

Another variation that occurred to me which sacrifices some information density for perhaps a more natural form is what I have called a 'Multi-Level Pie Chart'. I created an implementation of this technique and found it a reasonably satisfying approach for visually exploring hierarchical data. I'll describe it in detail in a future post. If you just can't wait any longer then you can get some flavour of the idea by investigating the Sunburst Project from Georgia Tech.


Map of the Market
World Population Treemap