使用 ggplot2 在世界地图中绘制子区域

Question

我正在尝试从名为 data:

的数据框中绘制这些国家/地区

               country value        lon        lat
1              Denmark    12   9.501785  56.263920
2     UK:Great Britain    13  -1.174320  52.355518
3               France    15   2.213749  46.227638
4              Germany    17  10.451526  51.165691
5      China:Hong Kong    18 114.174695  22.278315
6          Netherlands    31   5.291266  52.132633
7          New Zealand    32 174.885971 -40.900557
8  UK:Northern Ireland    33  -6.492314  54.787715
9               Norway    34   8.468946  60.472024
10        Saudi Arabia    40  45.079162  23.885942
11              Serbia    41  21.005859  44.016521
12           Singapore    42 103.819836   1.352083
13     Slovak Republic    43 101.724578   3.153870
14            Slovenia    44  14.995463  46.151241
15        South Africa    45  22.937506 -30.559482

我正在使用世界地图和 ggplot 库：

library(maps)       # Provides functions that let us plot the maps
library(ggplot2)    # Generic graphis engine

map = map_data("world")
map = subset(map, region!="Antarctica") #Remove Antarctica from map

Countries = ggplot() + 
  geom_polygon(data = map, aes(x=long, y = lat, group = group), fill = NA, colour="darkgray", size=0.5)+
  geom_map(data=data,map=map,aes(map_id=country, x=lon, y=lat),fill = "cornflowerblue", colour = "gray") +
  coord_equal()
Countries

我可以绘制除 UK:Great Britain、China: Hong Kong 以外的所有国家，实际上所有其他区域和次区域由“:”分隔：

我运行没有关于如何使用 world_map 和 ggplot 绘制 UK:Great Britain 的想法。大家有遇到过类似的问题，或者能想到解决办法吗？提前致谢。

Answer 1

这实现了您正在寻找的结果，但我不确定它是否是一个非常有用的地图

library(ggplot2)
library(data.table)
library(magrittr)

map_dat <- subset(map_data("world"), region!="Antarctica")
setDT(map_dat)

# the countries you need to translate to region:subregion
colon_countries <-
  grep(':', data$country, value=T) %>%
    sub(':.*$', '', .) %>%
    unique

# change region to region:subregion, 
# for countries of interest, for rows with a value of subregion
map_dat[region %in% colon_countries, 
        region := ifelse(!is.na(subregion),
                         paste0(region, ':', subregion),
                         region)]
ggplot() + 
  geom_polygon(data = map_dat,
               aes(x=long, y = lat, group = group),
               fill = NA, colour="darkgray", size=0.5)+
  geom_map(data = data, map = map_dat,
           aes(map_id = country),
           fill = "cornflowerblue", colour = 'gray') +
  # probably not the projection you really want, but leaving it to match your post above
  coord_equal()

Answer 2

geom_map 会将 data$country 中的条目匹配到 map$region。不幸的是 map_data 用第一个冒号分割区域，所以你得到 "UK" 与 data$country.

中的 "UK:Great Britain" 不匹配

一个可能的手动修复是这样更正：

map$region[which(map$subregion == "Great Britain")] <- "UK:Great Britain"
map$region[which(map$subregion == "Northern Ireland")] <- "UK:Northern Ireland"
map$region[which(map$subregion == "Hong Kong")] <- "China:Hong Kong"

使用 ggplot2 在世界地图中绘制子区域

Ploting subregions in wordmap with ggplot2

maps

r