Visualisation of airport connectivities in R using ggmap/ggplot/igraph

airport.r

library(ggmap)
airports <- read.csv(“https://raw.githubusercontent.com/jpatokal/openflights/master/data/airports.dat", header = FALSE)
names(airports) <- c(“id”, “name”, “city”, “country”, “code”, 
 “icao”, “lat”, “lon”, “altitude”, “timezone”, 
 “dst”,”tz”)
location <- c( 115,0 )
location
map <- get_map(location, zoom=3,maptype=’toner-lite’)
p <- ggmap(map) 
p
routes = read.csv(“https://raw.githubusercontent.com/jpatokal/openflights/master/data/routes.dat",header=FALSE)
names(routes) <- c(“airline”, “airlineID”, “sourceAirport”, “sourceAirportID”, 
 “destinationAirport”, “destinationAirportID”, “codeshare”, 
 “stops”, “equipment”)
routes = routes[,c(4,6,1:3,5,7:9)]
w = union(which(routes$sourceAirportID==”\\N”),which(routes$destinationAirportID==”\\N”))
routes = routes[-w,]
flights = graph.data.frame(routes,vertices=airports)
E(flights)$weight = 1
flights = simplify(flights)

yrange=ggplot_build(p)$panel$ranges[[1]]$y.range 
xrange=ggplot_build(p)$panel$ranges[[1]]$x.range
w = which(V(flights)$lon>xrange[1] & V(flights)$lon<xrange[2] 
 & V(flights)$lat>yrange[1] & V(flights)$lat<yrange[2])
G=induced_subgraph(flights,w)
G$layout = cbind(V(G)$lon,V(G)$lat)
E(G)$color = rgb(0,0,0,E(G)$weight/30)
plot_vector<- as.data.frame(cbind(V(G)$lon,V(G)$lat))
edgelist <- get.edgelist(G)
edgelist[,1]<-as.numeric(match(edgelist[,1],V(G)$name))
edgelist[,2]<-as.numeric(match(edgelist[,2],V(G)$name))
edges <- data.frame(plot_vector[edgelist[,1],], plot_vector[edgelist[,2],],E(G)$color)
colnames(edges) <- c(“X1”,”Y1",”X2",”Y2",”Color”)
p + geom_segment(aes(x=X1, y=Y1, xend = X2, yend = Y2), data=edges, size = 0.5, colour=edges$Color) + geom_point(aes(V1, V2), data=plot_vector)+ geom_point(aes(x=V1,y=V2),plot_vector,size=0.01,alpha=0.5,color=”yellow”)

https://medium.com/@infinex/visualisation-of-airport-connectivities-in-r-using-ggmap-ggplot-igraph-d26af3267ca1