Efficient Visual Navigation of Hierarchically Structured Graphs
Marcus Raitner, Prof Dr, Franz Josef Brandenburg · 2006
isual navigation of hierarchically structured graphs is a technique for interactively exploring large graphs that possess an additional hierar- chical structure. This structure is expressed in form of a recursive clustering of the nodes: in call graphs of telephone networks, for instance, the nodes are identified with phone numbers; they are clustered recursively through the implicit structure of the numbers, e. g., nodes with the same area code belong to a cluster. In order to reduce the complexity and the size of the graph, only those subgraphs that are currently needed are shown in detail, while the others are collapsed, i. e., represented by meta nodes. In such a graph view the subgraphs in the areas of interest are expanded furthest, whereas those on the periphery are abstracted. As the areas of interest change over time, clusters in a view need to be expanded or contracted.