A layout algorithm for undirected compount graphs

Abstract

Graph layout is an important problem in information visualization. All datadriven graph-based information visualization systems require some sort of an automatic geometry generation mechanism, as it is generally not directly available from the data being modeled. This is why graph layout problem has been studied extensively. However, for the case of compound graphs, there are still important gaps in this area. We present a new, elegant algorithm for undirected compound graph layout. The algorithm is based on the traditional force-directed layout scheme with extensions to handle nesting, varying node sizes, and possibly other application-specific constraints. Experimental results show that the execution time and quality of the produced drawings with respect to commonly accepted layout criteria are quite satisfactory. The algorithm has also been successfully implemented as part of a pathway integration and analysis toolkit named Patika for drawing complicated biological pathways with compartmental constraints and arbitrary nesting relations to represent molecular complexes and various types of pathway abstractions.