Author Network Graph

Posted on 2 mins read

Code from Eiko Fried
View my author network at the bottom of my publications page

library(scholarnetwork)
library(igraph)
library(ggplot2)
d <- extractNetwork(id="tW1w9JEAAAAJ", n=500) # google scholar ID
str(d)

plotNetwork(d$nodes, d$edges, file="network.html")

# cleaning network data
network <- graph_from_data_frame(d$edges, directed=FALSE)
set.seed(123)
l <- layout.fruchterman.reingold(network, niter=1500) # layout
fc <- walktrap.community(network) # community detection

# node locations
nodes <- data.frame(l); names(nodes) <- c("x", "y")
nodes$cluster <- factor(fc$membership)
nodes$label <- fc$names
nodes$degree <- degree(network)

# edge locations
edgelist <- get.edgelist(network, names=FALSE)
edges <- data.frame(nodes[edgelist[,1],c("x", "y")], nodes[edgelist[,2],c("x", "y")])
names(edges) <- c("x1", "y1", "x2", "y2")

# and now visualizing it...
p <- ggplot(nodes, aes(x=x, y=y, color=cluster, label=label, size=degree))
pq <- p + geom_text(color="black", aes(label=label, size=degree),
                    show_guide=FALSE) +
  # nodes
  geom_point(color="grey20", aes(fill=cluster),
             shape=21, show_guide=FALSE, alpha=1/2) +
  # edges
  geom_segment(
    aes(x=x1, y=y1, xend=x2, yend=y2, label=NA),
    data=edges, size=0.25, color="grey20", alpha=1/5) +
  ## note that here I add a border to the points
  scale_fill_discrete(labels=labels) +
  scale_size_continuous(range = c(5, 8)) +
  theme(
    panel.background = element_rect(fill = "white"),
    plot.background = element_rect(fill="white"),
    axis.line = element_blank(), axis.text = element_blank(),
    axis.ticks = element_blank(),
    axis.title = element_blank(), panel.border = element_blank(),
    panel.grid.major = element_blank(),
    panel.grid.minor = element_blank(),
    legend.background = element_rect(colour = F, fill = "black"),
    legend.key = element_rect(fill = "black", colour = F),
    legend.title = element_text(color="white"),
    legend.text = element_text(color="white")
  ) +
  ## changing size of points in legend
  guides(fill = guide_legend(override.aes = list(size=5)))

pq