For such cases Treemap is a powerful visualization tool. This paper is an introduction to treemap. Tutorial Tree visual structures usually represent hierarchical data in two ways, by using connection or by using containment. Trees shows link between nodes and its sub nodes and one common way to do this is by drawing connecting lines between nodes and its sub-nodes, for example we show family tree using this technique.
Space is wasted in visually organizing the nodes.
As trees get large they may require an extreme aspect ratio that makes it difficult to display. The treemap visualization technique, developed by Ben Shneiderman at HCIL, University of Maryland College Park, presents a novel method to respond to visualizing hierarchical information. In this method nodes, whose attributes are of more importance are given more display area. Users have the choice to define the leaf node attribute that determines space allocation. This is illustrated in the case of statistics for 50 US states.