Michael Burch, Stephan Diehl, Fabian Beck and Felix Bott from the University of Trier developed two new visualization method to display directed and weighted graphs where the nodes correspond to leaves in a hierarchy.
The TimeRadarTrees approach shows the information hierarchy as a traditional node-link diagram, but in a radial style. Each graph is represented as a slice on the inner circle and corresponding slices on the smaller outer circles, which we call thumbnails. The inner circle shows the incoming edges, the thumbnails represent the outgoing edges.
TimeLineTrees are very similar to TimeRadarTrees: the visualization consists of the same components, but they are arranged in a non-radial layout. The hierarchy is represented by a tree diagram on the left hand side, the sequences of transactions on the right hand side, and the thumbnails are positioned in between. It is reduced to represent sequence of transactions (cliques) instead of sequences of arbitrary graphs.