PieTree

The PieTree is an interactive constant area visualisation for hierarchical data with some form of numerical attribute including values at the nodes – for example in a website where there are visits to both the main page of a section and also to sub-pages. The visualisation starts off like a standard pie chart where each segment represents a branch of the tree (e.g. section of the site), except there is also a small circle in the middle representing the value at the root (e.g home page). If any of the segments is selected it breaks into smaller segments for each sub-branch, and so on.

Used on pages 135, 136

Also known as pietree