The Journal of Social Structure has released its First Annual JoSS Visualization Symposium results and two of the images were generated with NodeXL. One of the two is Bernie Hogan’s radial layout applied to representing Facebook Friend networks.
The Journal of Social Structure (JoSS) is an electronic journal of the International Network for Social Network Analysis (INSNA). Here is Bernie’s description of the graph.
This is a “pinwheel” diagram using the author’s Facebook personal network (captured July 15, 2009).
Nodes represent the author’s friends and links represent friendships among them. The author is not shown. Each ‘wing’ radiating outwards is a partition using a greedy community detection algorithm (Wakita and Tsurumi, 2007). Wings are manually labelled. Node ordering within each wing is based on degree. Node color and size is also based on degree. Nodes position is based on a polar coordinate system: each node is on an equal angle of n/360º with a radius being a log-scaled measure of betweenness. Higher values are closer to the center indicating a sort of cross-partition ‘gravity’.
This layout has several notable features:
– The angle of each wing is proportionate to its share of the network. Thus 25 percent of nodes go from 0 to 90º.
– Partitions are distinguished by their position rather than a node’s color or shape.
– The tail indicates the periphery of each partition. A wing with many tail nodes indicates many people who are only tied to other group members.
– Edges crossing the center show between-partition connections. Since nodes are sorted by degree it is easy to see if edges originate from the most highly connected nodes or the entire partition.
Bernie’s chapter on analyzing Facebook networks with NodeXL appears in the book: Analyzing Social Media Networks with NodeXL: Insights from a connected world.