我想画一张法国各省(即法国的地区)的地图和地图上的plot point。我使用ggplot2来绘制地图,但当我想在地图上添加点时,R返回一个错误,说它找不到"组"。
library("ggplot2")
library("ggmap")
# load the contour of French departements
wg <- read.csv("data/departements.csv")
metropoles <- c("Paris", "Rennes", "Rouen", "Lille", "Marseille")
geo <- geocode(metropoles)
met <- data.frame(ville = metropoles, geo)
map <- ggplot(data = wg, aes(x = long, y = lat, group = group)) +
geom_polygon() +
scale_x_continuous(limits = c(-7,10)) +
scale_y_continuous(limits = c(40,53)) +
coord_map() +
theme(axis.text = element_blank(), axis.title = element_blank())
map + geom_point(data = met, aes(x = lon, y = lat))
对于复制,您可以在这里找到原始数据,在这里找到R程序
@Roland有很好的答案。问题是我把group定义为一般参数。
ggplot() +
geom_polygon(data = wg, aes(x = long, y = lat, group = group)) +
scale_x_continuous(limits = c(-7,10)) +
scale_y_continuous(limits = c(40,53)) +
coord_map() +
theme(axis.text = element_blank(), axis.title = element_blank())
geom_point(data = met, aes(x = lon, y = lat))