Starting from the Edge List with igraph

In this exercise, we will learn how to create a network object from an edge list using the igraph package in R.

Generating Data

First, we need to generate some data in the form of an edge list.:

edge_list <- rbind(
  c(1,2),
  c(1,3),
  c(2,3),
  c(2,4),
  c(3,2),
  c(5,3)
)

Creating a Network Object

Now that we have our edge list, we can create a network object from it using the graph.edgelist() function from the igraph package:

edge_network <- graph.edgelist(edge_list)

Setting Node and Edge Attributes In the igraph package, we use the V() and E() functions to access and set vertex and edge attributes, respectively. Here’s how to set the node names and assign a value to each edge:

V(inet2)$name <- c("A", "B", "C", "D", "E")
E(inet2)$val <- c(1:6)

Switching Between Packages

It’s also possible to switch between the igraph package and the network package using the intergraph package. Here’s how to convert an igraph object to a network object and vice versa:

p_load(intergraph)
# Convert igraph object to network object
edge_network <- asNetwork(edge_network)
# Convert network object to igraph object
edge_network <- asIgraph(edge_network)