R：創建世界網絡圖

Question

我想生成一個類似於the one below from this page的R世界網絡圖。

我一直在尋找的R包，讓我這樣做，但我一直沒能找到一個。有D3 JavaScript Network Graphs from R，但我找不到世界網絡地圖示例。
如何在R中創建類似的東西？

Answer 1

好，FWIW：這裏有一個快速的&骯髒的方式在地圖上繪製的頂點（「城市」）和連接頂點之間的邊緣與箭頭：

library(maps) 
library(diagram) 
library(plotrix) 
palette(rainbow(20)) 
data("world.cities") 

pdf(tf <- tempfile(fileext = ".pdf"), width = 40, height = 20) 

map('world', fill = TRUE, col = "lightgray", mar = rep(0, 4)) 

nodes <- transform(with(world.cities, world.cities[pop > 5e6,]), country.etc = as.factor(country.etc)) 
with(nodes, points(long, lat, col=country.etc, pch=19, cex=rescale(pop, c(1, 8)))) 

set.seed(1) 
edges <- subset(data.frame(from = sample(nodes$name, 20, replace = TRUE), to = sample(nodes$name, 20, replace = TRUE), stringsAsFactors = F), from != to) 
edges <- merge(merge(edges, nodes[, c("name", "long", "lat")], by.x = "from", by.y = "name"), nodes[, c("name", "long", "lat")], by.x = "to", by.y = "name") 
edges$col <- as.integer(nodes$country.etc[match(edges$from, nodes$name)]) 

apply(edges[, -(1:2)], 1, function(x) curvedarrow(to=x[3:4], from=x[1:2], lcol=x[5], curve=.1, arr.pos = 1, lwd=.5)) 

dev.off()   
shell.exec(tf) 

Answer 2

這裏是一個解決方案使用geosphere和maps包。 使用gcIntermediate函數可以「在用於定義大圓的兩點之間的大圓上的中間點」。

這裏是示出從JKF機場航班conncetions（樣本數據從nycflights13封裝dplyr過濾）的示例：

library(maps) 
library(geosphere) 
library(dplyr) 
library(nycflights13) 


usairports <- filter(airports, lat < 48.5) 
usairports <- filter(usairports, lon > -130) 
usairports <- filter(usairports, faa!="JFK") 
jfk <- filter(airports, faa=="JFK") 

map("world", regions=c("usa"), fill=T, col="grey8", bg="grey15", ylim=c(21.0,50.0), xlim=c(-130.0,-65.0)) 


for (i in (1:dim(usairports)[1])) { 

inter <- gcIntermediate(c(jfk$lon[1], jfk$lat[1]), c(usairports$lon[i], usairports$lat[i]), n=200) 

lines(inter, lwd=0.1, col="turquoise2")  
} 

points(usairports$lon,usairports$lat, pch=3, cex=0.1, col="chocolate1") 

這是基於貼在一個教程我的blog。