Visual analysis of compound graphs

Compound graphs consist of two separate components. On the one hand a graph structure describes which elements are related to each other and to what extent, i.e., inherent edge weights and directions may exist, which we refer to as adjacency edges. On the other hand the graph elements are not only related by adjacencies, but they are also hierarchically organized which might be considered another kind of relationship among the graph vertices. Those relations are further referred to as inclusion edges. There are various application domains in which such a data structure occurs and with which a data analyst has to deal, either analytically on the basis of algorithms or visually, i.e., more on the basis of diagrams and visual languages. In this paper we introduce a visualization tool that is able to provide linked views on both aspects, i.e., the graph relations and the hierarchical organization. We illustrate the usefulness of our tool in a case study investigating soccer team results that build weighted directed adjacency relations in a hierarchically structured world.