6.4 From data to networks

suppressPackageStartupMessages(library(igraph))

#edge list
personA <- c("Mark", "Mark", "Peter", "Peter", "Bob", "Jill")
personB <- c("Peter", "Jill", "Bob", "Aaron", "Jill", "Aaron")

edgelist <- cbind(PersonA = personA, PersonB = personB)

print(edgelist)

##      PersonA PersonB
## [1,] "Mark"  "Peter"
## [2,] "Mark"  "Jill" 
## [3,] "Peter" "Bob"  
## [4,] "Peter" "Aaron"
## [5,] "Bob"   "Jill" 
## [6,] "Jill"  "Aaron"

#adjacency matrix
adjacency <- matrix(c(0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0),
                    nrow = 5,
                    ncol = 5,
                    dimnames = list(c("Mark", "Peter", "Bob", "Jill", "Aaron"),
                                    c("Mark", "Peter", "Bob", "Jill", "Aaron")))

print(adjacency)

##       Mark Peter Bob Jill Aaron
## Mark     0     1   0    1     0
## Peter    1     0   1    0     1
## Bob      0     1   0    1     0
## Jill     1     0   1    0     1
## Aaron    0     1   0    1     0

Edge list into a network object.

network <- graph.edgelist(edgelist, directed=FALSE)
network

## IGRAPH 3e8ebd5 UN-- 5 6 -- 
## + attr: name (v/c)
## + edges from 3e8ebd5 (vertex names):
## [1] Mark --Peter Mark --Jill  Peter--Bob   Peter--Aaron Jill --Bob  
## [6] Jill --Aaron

Adjacency matrix to network object.

network_adj <-graph.adjacency(adjacency,mode = "undirected" )

• UN: undirected
• DN : directed
• #vertices #edges

Vertices of network

V(network)

## + 5/5 vertices, named, from 3e8ebd5:
## [1] Mark  Peter Jill  Bob   Aaron

Edges of network

E(network)

## + 6/6 edges from 3e8ebd5 (vertex names):
## [1] Mark --Peter Mark --Jill  Peter--Bob   Peter--Aaron Jill --Bob  
## [6] Jill --Aaron

We can visualize the network using the plot() function.

plot(network)