How to write in a membership vector to use in modularity() function with R

Question

I have a membership vector created with another software and I am stuck to write it into R so that I can use iGraph' modularity function to calculate modularity of this community division．　

Can someone help me with how to write the vector into R so that the Modularity(g,membership） could run?

I tried with using membership <- read.table(file), but the result could not be used with Modularity(g, membership)

Thanks,

Song

Answer 1

read.table creates a data frame, you need to convert that to a simple numeric vector. Alternatively you can use scan(). You might need to adjust the following to your data format.

library(igraph)
G <- graph.full(3) + graph.ring(3) + graph.full(3)

contents <- '1 1 1 2 2 2 3 3 3'
memb <- scan(textConnection(contents))
# Read 9 items

modularity(G, memb)
# [1] 0.6666667

Instead of the textConnection(), just put your file name there.