Graphs are made of nodes and edges. In SEO nodes are webpages and edges, links directed to them from other webpages on the graph.

library(igraph) dat=read.csv(file.choose(),header=TRUE) # choose an edgelist in .csv file format g=graph.data.frame(dat,directed=TRUE) transitivity(g)

Transitivity or clustering coefficient is the probability that the adjacent vertices of a vertex are connected.

Count vertices vcount(graph)

Count edges ecount(graph)

Diameter

diameter(graph)

The diameter of a graph is the length of the longest geodesic.

Graph density

graph.density(graph)

The density of a graph is the ratio of the number of edges and the number of possible edges.

Find more about plotting directed graphs here.