ABSTRACT
A circular drawing of a graph (see Figure 9.1 for an example) is a visualization of a graph with the following characteristics:
• The graph is partitioned into clusters; • The nodes of each cluster are placed onto the circumference of an embedding circle; and
• Each edge is drawn as a straight line. There are many applications that would be strengthened by an accompanying circular
graph drawing. For example, the drawing techniques could be added to tools which manipulate telecommunication [Ker93], computer [Six00], and social networks [Kre96] to show clustered views of those information structures. The partitioning of the graph into clusters can show structural information such as biconnectivity, or the clusters can highlight semantic qualities of the network such as sub-nets. Emphasizing natural group structures within the topology of the network is vital to pinpoint strengths and weaknesses within that design. It is essential that the number of edge crossings within each cluster remains low in
Figure 9.1 A graph with arbitrary coordinates for the nodes and a circular drawing of the same graph as produced by an implementation of Algorithm CIRCULAR. Figure taken from [ST99, ST06].
