Pictures of graphs

A 5-regular graph

A (non-authoritative) diagram of heritage of the Unix operating system. This "crazy" version of the classic graph was created to stress test the polygon shape generator and color map manager with random values.

The graph file was generated automatically from a session with the LDBX graphical interface to the standard DBX debugger. Nodes are drawn with the 'record' shape. Labels of this shape are interpreted specially as nested horizontal and vertical box lists formatted as tables. In a record label, curly braces { } enclose lists, vertical bar | separates list items, and creates a port identifier for attaching edges. Edges are also labeled with 'id' attributes. Though not demonstrated in this particular file, these attributes allow referencing multiple (parallel) edges between the same node pair.

This a random subgraph of the Erdos' 2nd neighborhood Collaboration graph. The size of this subgraph is about 2500. It illustrates the shape of the power law graph --- an 'octupus' with a dense core and long legs. The structure has been proved in a PNAS paper in 2002.

This image is a visualization of Jeffrey Heer's personal friendster network to 3 hops out, an online social network consisting of Jeffrey, his "friends", his friends' friends, and his friends' friends' friends. The resulting networks consist of 47471 people connected by 432430 friendship relations.

2001 computer graphics

This large graph shows the router level connectivity of the Internet as measured

by Hal Burch and Bill Cheswick's Internet Mapping Project.

The graph represents dependencies between modifications to a large program. Because testing such programs is difficult and expensive, the graph was made to discover which subsets of modifications might

be tested separately by understanding or even eliminating a few key dependencies.

Some familiar graphs

Thanks to Helen Purchase