Network Analysis Using iGraph in R

Reference: https://assemblingnetwork.wordpress.com/2013/05/29/network-basics-with-r-and-igraph-part-i-of-iii/

#load the library

library(igraph)

# following code builds network with two nodes, with A related to B

graph.twonodesonelink<-graph.formula(A-+B)

#following code helps you visualize the graph

plot.igraph(graph.twonodesonelink)

#following code plots graph with four nodes

graph.testchain<-graph.formula(A-+C,B-+C,C-+D)

# following code plots the above graph:

plot.igraph(graph.testchain)

#Read data – first two columns spanning rows 1814 to 1906 from the following excel file # which is stored in the R working directory

otago.graph.part1<-graph.edgelist(as.matrix(otago.links.data[1814:1906,1:2]))
# Get the network web into matrix form

otago.adjmatrix.part1<-get.adjacency(otago.graph.part1,sparse=F)

# Get the basic network indices from the matrices with GenInd()

ind.otago.part1<-GenInd(otago.adjmatrix.part1)

#plot the above matrix

par(mar=c(.1,.1,.1,.1))

plot.igraphotago.graph.part1,vertex.label=NA,vertex.size=3,edge.arrow.size=.25,layout=layout.circle)