Chapter 1. Getting to know graph visualization
Figure 1.1. A property graph of a single email between Enron executives. The two nodes are the sender and recipient of the email, and the directed edge is the email.
Figure 1.2. A simple property graph with two nodes and an edge. Stella (the first node) bought a 2008 Volkswagen Jetta (the second node) in September 2007 and sold it in October 2013. Modeling it as a graph highlights that Stella had a relationship with this car (the edge).
Figure 1.3. A graph of some of the Enron executives’ email communications. You can easily see that Timothy Belden is a hub of communication in this segment of Enron, sending and receiving email from many other executives.
Figure 1.4. The Seven Bridges of Königsberg problem. Using this map of the bridges of Königsberg, Prussia, try to draw a route that reaches each area of the city but never crosses the same bridge twice.
Figure 1.5. Seven bridges and four land areas of Königsberg as a graph. In this graph, nodes denote the land masses bordering the Pregel River and the two islands in its middle. Edges represent the bridges connecting the two islands and two shorelines.
Figure 1.6. Graphing a single email at Enron
Figure 1.7. Using a graph to illustrate a table of name/country pairs
Figure 1.8. A graph of driving times between North American cities. A graph is not an effective way of presenting this type of data because in reality everything is connected to everything else.