CODEWITHSUNDEEP
r
eli
eli

Reputation: 184

plot a subset of igraph data , just subset by their attribute

I have a fblog data set ,PolParty is one attribute of my data, I want to plot just 2 political parties (say P1 and P2) and plot the network of blogs. i wrote code below but i think it is wrong , can some one help me?

library(statnet)
library(igraph)
library(sand)
data(fblog)
fblog = upgrade_graph(fblog)

class(fblog)
summary(fblog)
V(fblog)$PolParty
table(V(fblog)$PolParty)
p1<-V(fblog)[PolParty=="PS"] # by their labels/names
p2<-V(fblog)[PolParty=="UDF"]
class(p1)

Upvotes: 0

Views: 635

Answers (1)

Chris
Chris

Reputation: 310

The objects p1 and p2 that you were creating are of the class igraph.vs (instead of igraph). This object just documents the vertices. Which is not a full graph. Hence when you try to plot it you don't get anything. Based on the following post: Subset igraph graph by label

g=subgraph.edges(graph=fblog, eids=which(V(fblog)$PolParty==" PS"), delete.vertices = TRUE)
plot(g)

The above works. NOTE: regarding the output of V(fblog)$PolParty- everything is preceeded by a space hence you need to use V(fblog)$PolParty==" PS"

UPDATE: if I want to subset based on 2 conditions- I will modify the which() command:

g=subgraph.edges(graph=fblog, eids=which(V(fblog)$PolParty==" PS"| V(fblog)$PolParty==" UDF"), delete.vertices = TRUE)
plot(g)

enter image description here

Upvotes: 1

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