A radial network diagram of Les Miserables characters with hierarchical edge bundling. Nodes are ordered and grouped by the first chapter the character appeared in.
Radial layouts can be useful for seeing patterns between and within groups. For example, we can see that all the characters in Vol 1, Book 3, Chapter 4 only interact with each other, Fantine, and Felix Tholomyes. However, this layout has difficulty scaling to hundreds of nodes, and edge bundling can make it difficult to count the number of links connecting to each node.
A related visualization is the chord diagram, which shows aggregated connections between groups.