To get the iGraph package from CRAN:
install.packages("igraph")
To get the extensions from github:
# install.packages("devtools")
devtools::install_github("TomKellyGenetics/info.centrality")
#Compute efficiency of the network
network.efficiency(graph)
#Compute vertex information centrality for each vertex in the network
info.centrality.vertex(graph)
#Compute network information centrality
info.centrality.network(graph)