Labeled object treemap: A new graph labeling based technique for visualizing multiple hierarchies

Abstract

ormation visualization is a class of techniques which is used to present data in a graphical or pictorial format. Identification of new patterns as well as an understanding of difficult concepts is possible with the proper use of visualization. Using interactive visualization, various other details related to the information can be obtained. In this paper, we consider trees in which each node is related to a leaf node (object) of taxonomy. We propose a new technique of visualization namely �Labeled Object Treemap� for the visualization of multiple hierarchies. In our approach, a unique label is associated with each node and this label will convey all the necessary information including adjacency as well as non-adjacency with the other nodes of the tree. The comparison of our proposed technique with already known techniques is also made. Here we develop and use a labeling of trees where vertices represent distinct sets and adjacency coincides with disjointness. The total number of distinct elements used in the underlying labeling is asymptotically minimized. The motivation of selecting set labeling is to use cardinalities of labels to identify level numbers of the underlying tree using which it will be easier to discover adjacency as well as non-adjacency for all vertices. Our motivation to look at disjointness instead of intersection is that several well-known graphs like the Petersen graph and Kneser graphs are expressed in the latter method. Our main contribution is the development of a new visualization technique which solves the issues of edge crossing and continuity of the 'Trees in a treemap' visualization technique while maintaining all the good characteristics of existing methods for visualizing multiple hierarchies. Additional features are also discussed using the modified labeling algorithm.