如何用GEOM_MAP用各自的国旗填充国家？

Question

我正在使用软件包ggplot2，并使用函数geom_map to 填充具有不同颜色的国家。

我想知道是否可以用标志而不是颜色填充？

所需结果：

我正在做：

ALL_EU <-c("Russia", "Germany", "UK", "France", "Italy", "Spain", "Ukraine", "Poland", "Romania", "Netherlands", "Belgium", "Czech Republic", "Greece", "Portugal", "Sweden", "Hungary", "Belarus", "Austria", "Serbia", "Switzerland", "Bulgaria", "Denmark", "Finland","Slovakia", "Norway", "Ireland", "Croatia", "Moldova", "Bosnia and Herzegovina","Albania", "Lithuania", "North Macedonia", "Slovenia", "Latvia", "Estonia","Montenegro", "Luxembourg"  , "Malta", "Iceland", "Andorra", "Monaco", "Liechtenstein","San Marino", "Vatican", "Kosovo")

#Filter some regions out just for plot
world_map <- map_data("world",region = ALL_EU[-which(ALL_EU%in%c("Russia","Iceland"))])
world_map <- world_map%>%filter(subregion!="Svalbard"&subregion!="Jan Mayen"|is.na(subregion))

然后绘制它，请注意，在这种情况下，我使用fill = “标志”因此，我可以用scale_fill_manual更改颜色和传奇，也可以使所有国家/地区蓝色仅用于一个可复制的示例。

ggplot() +
    theme_void()+
    geom_map(dat = world_map,map = world_map, 
             aes(map_id = region,fill = "Flags"),color = "gray",size = 0.25)+
    scale_fill_manual(name = "Countries", values = c("Flags" = "blue"))+
    expand_limits(x = world_map$long, y = world_map$lat)

也，即使可能，也可以将几个国家填满，例如欧盟的旗帜。但这可能是另一个问题。谢谢你！

Answer 1

这是一个选项，使用优点 ggpattern 和 flagon 软件包。

# Get mapping of country codes to countries; need this to select the right
# flags by country codes as provided by `flagon`
# Must also clean up country names to match those from `world_map`
library(tidyverse)
library(flagon)
data_flags <- flagon::country_codes %>%
    select(country, ccode) %>%
    mutate(flag = flagon::flags(ccode)) %>%
    mutate(country = case_when(
        str_detect(country, "Macedonia") ~ "North Macedonia",
        str_detect(country, "Moldova") ~ "Moldova",
        str_detect(country, "Vatican") ~ "Vatican",
        str_detect(country, "United Kingdom") ~ "UK",
        TRUE ~ country)) %>%
    filter(country %in% ALL_EU)
    

library(ggpattern)
world_map %>%
    left_join(data_flags, by = c("region" = "country")) %>%
    filter(!is.na(flag)) %>%
    ggplot() +
    theme_void() +
    geom_map_pattern(
        map = world_map,
        aes(map_id = region, pattern_type = region, pattern_filename = I(flag)), 
        pattern = "image",
        pattern_type = "expand",
        color = "gray", 
        size = 0.25) +
    expand_limits(x = world_map$long, y = world_map$lat)