r - 如何用 r 中的地区映射印度州？

Question

我想在 R 软件中用各自的地区绘制印度的不同州。我尝试使用 GADM，2 级数据来获取坐标。

我已关注此主题 Mapping just one State of India and writing its name inside the state boundary .但是，我无法对任何州的数据进行子集化并将其用于映射。

我尝试过的:

map <- fortify(Karnataka)
map$id <- as.integer(map$id) 
dat <- data.frame(id = 216:242, district = Karnataka) 
map_df <- inner_join(map, dat, by = "id") 
centers <- data.frame(gCentroid(Karnataka, byid = TRUE)) 
centers$state <- dat$district

Answer 1

我可以使用以下命令绘制一个州及其地区边界的 map 。

India <- getData("GADM", country = "India", level = 2)  
Karnataka <- subset(India, NAME_1 == "Karnataka")
map <- fortify(Karnataka);  
map$id <- as.integer(map$id);  
dat <- data.frame(id = 216:242, district = Karnataka@data$NAME_2);  
map_df <- inner_join(map, dat, by = "id");  
centers <- data.frame(gCentroid(Karnataka, byid = TRUE));  
centers$state <- dat$district;  


ggplot() +
geom_map(data = map_df, map = map_df,
     aes(map_id = id, x = long, y = lat, group = group),
     color = "#ffffff", fill = "#bbbbbb", size = 0.25) +
geom_text(data = centers, aes(label = state, x = x, y = y), size = 2) +
coord_map() + labs(x = "", y = "", title = "Districts of Karnataka")