We are now going to explore the three graphs, and introduce an important property of a network node, which is the degree of the node.
The degree of a node represents the number of links it has to other nodes. In a directed graph, we can make a distinction between the incoming degree of a node or an in-degree, which is the number of its incoming links, and its outgoing degree or out-degree, which is the number of nodes that it points to. In the following sections, we will explore the degree distributions of the three example networks.
For the Enron email network, we can confirm that there are roughly ten times more links than nodes:
scala> emailGraph.numEdges ...