Treemap

A treemap turns a tree in graph theory into a planar space-filling map: the root is the outermost rectangle, whose nodes are the rectangles at level one, and so on down the levels.

Treemaps visually display a hierarchical structure by dividing a rectangular area in proportion to the values of the tree nodes. Treemaps were invented by Ben Shneiderman in 1990.

This Demonstration uses a splice and dice algorithm with a split parameter determining when to switch reducing the

x

axis or the

y

axis of the remaining rectangular area. The tree depth here is four—you control how many branching levels are visible—and consists of six randomly generated values at each node.