Drawing Clusters and Hierarchies

Large graphs such as WWW connection graphs or VLSI schematics cannot be drawn in a readable way by traditional graph drawing techniques. An approach to solve this problem is, for example, fish-eye representation, which allows one to display a small part of the graph enlarged while the graph is shown completely (see e.g. Formella and Keller (1995)). Another way is drawing only a part of the graph. The method presented here is clustering, that is grouping the vertex set.