Navigating Clustered Graphs Using Force-Directed Methods

Graphs which arise in Information Visualization applications are typically very large: thousands, or perhaps millions of nodes. Current graph drawing methods successfully deal with (at best) a few hundred nodes. This paper describes a strategy for the visualization and navigation of graphs. The strategy has three elements: 1. A layered architecture, called CGA, for handling clustered graphs: these are graphs with a hierarchical node clustering superimposed. 2. An online force-directed graph drawing method. 3. Animation methods. Using this strategy, a user may view an abridgment of a graph, that is, a small part of the graph that is currently of interest. By changing the abridgment, the user may travel through the graph. The changes use animation to smoothly transform one view to the next. The strategy has been implemented in a prototype system called DA-TU. Communicated by G. Liotta and S. H. Whitesides: submitted September 1998; revised July 2000. Eades and Huang, Navigating Clustered Graphs, JGAA, 4(3) 157–181 (2000)158