I do not understand the calculation of transitivity of global type. transitivity(g, type="global")
In the manual of igraph with R, it is wrote that "The global transitivity of an undirected graph. This is simply the ratio of the triangles and the connected triples in the graph. "
Then I tried a simple graph, which is a ring of 7 vertices with an additional edge " 0 -- 2 " gring_1 <- add.edges( graph.ring(7), c(0, 2) )
The number of triple in gring_1 should be choose(7, 3) = 35
and the number of triangle gring_1 should be 1 only. Then I think the transitivity is 1/35 = 0.02857143