How to split an igraph into connected subgraphs?

Question

I have an igraph with several disconnected components. For example:

library(igraph)
g <- simplify(
  graph.compose(
    graph.ring(10), 
    graph.star(5         


        

Answer 1

You could calculate the connected components of your graph by using:

clusters(g)
# $membership
# [1] 1 1 1 1 1 1 2 2 3 1
# 
# $csize
# [1] 7 2 1
# 
# $no
# [1] 3

Or you could create a separate graph for each component of your graph by using:

dg <- decompose.graph(g) # returns a list of three graphs
plot(dg[[1]]) # plot e.g. the 1st one