2.1 Cyberspace representation

### 2.1.1 Representation with a graph

Therefore, we can see cyberspace as a finite set of resources with a relation between pairs of linked resources. It is possible to model this system with a connected graph where represent the vertices (nodes) and the edges (undirected arcs) between vertices of the graph. The size of is the number of edges, thus
.
The information in the graph may also be expressed in a variety of ways in matrix form. There is one such matrix, the adjacency matrix, that is especially useful. An adjacency matrix of the graph is of size . The entries in the adjacency matrix, , records which pairs of nodes are adjacent. If nodes and are adjacent, then , and if nodes and are not adjacent, then . The entries on the diagonal, values of , are undefined, because we do not allow loops in the graph.

The following elements are introduced to extract features and components of the graph :

Cyberspace geography visualization - 15 October 1995

Luc Girardin, The Graduate Institute of International Studies