Basic network diagram
It is a common task to make nodes bigger when they are heavily connected with other nodes. Indeed, it means they have an importance in the network and thus deserves to be highlighted.
The degree() function of the igraph package allows to compute the number of connection per node. It is possible to pass its result to the vertex.size argument of the plot() function to get the targeted result.
# library
library(igraph)
# create data:
links=data.frame(
source=c("A","A", "A", "A", "A","J", "B", "B", "C", "C", "D","I"),
target=c("B","B", "C", "D", "J","A","E", "F", "G", "H", "I","I")
)
# Turn it into igraph object
network <- graph_from_data_frame(d=links, directed=F)
# Count the number of degree for each node:
deg <- degree(network, mode="all")
# Plot
plot(network, vertex.size=deg*6, vertex.color=rgb(0.1,0.7,0.8,0.5) )
