使用 geom_polygon() 保留自定义颜色

Question

我用map() 绘制了一张带有自定义颜色的法国地图：

map(database="france", fill=TRUE, col=color)

结果：

（不要介意这两个错误）

然后我想使用ggplot2 包将这张地图与兰伯特的投影放在一起：

head(fortify(carte_france))
ggplot(map('france'), aes(long, lat, group = group)) +
  geom_polygon(col = 1) + 
  coord_map(projection = "lambert", parameters = c(lat0 = 41.366005 , lat1 = 51.097523))

但是它给了我这个：

我知道深色来自 geom_polygon() 的 arg fill 但有没有办法告诉函数 geom_polygon() 不使用 arg fill 或保留我之前放置的颜色？

颜色向量，color：

c("yellowgreen", "yellowgreen", "yellowgreen", "yellowgreen", 
"gold1", "sienna3", "yellowgreen", "yellowgreen", "sienna3", 
"gold1", "gold1", "gold1", "sienna3", "sienna3", "gold1", "dodgerblue2", 
"dodgerblue2", "dodgerblue2", "gold1", "dodgerblue2", "sienna3", 
"dodgerblue2", "burlywood2", "dodgerblue2", "palevioletred4", 
"dodgerblue2", "palevioletred4", "dodgerblue2", "palevioletred4", 
"palevioletred4", "gold1", "palevioletred4", "gold1", "darkorchid4", 
"gold1", "darkorchid4", "palevioletred4", "green4", "cyan4", 
"gold1", "palevioletred4", "burlywood2", "green4", "green4", 
"cyan4", "darkorchid4", "green4", "burlywood2", "palevioletred4", 
"burlywood2", "green4", "green4", "palevioletred4", "palevioletred4", 
"palevioletred4", "green4", "burlywood2", "olivedrab2", "green4", 
"olivedrab2", "darkorchid4", "darkorchid4", "cyan4", "darkorchid4", 
"cyan4", "cyan4", "olivedrab2", "olivedrab2", "olivedrab2", "cyan4", 
"cyan4", "olivedrab2", "cyan4", "olivedrab2", "olivedrab2", "cyan4", 
"cyan4", "olivedrab2", "olivedrab2", "olivedrab2", "cyan4", "cyan4", 
"cyan4", "cyan4", "orange2", "orangered1", "orangered1", "orangered1", 
"olivedrab2", "orange2", "olivedrab2", "orangered1", "orange2", 
"orangered1", "orange2", "orange2", "orangered1", "orangered1", 
"orangered1", "orange2", "orangered1", "orange2", "orangered1", 
"olivedrab2", "orangered1", "orangered1", "orangered1", "orangered1", 
"orange2", "orange2", "orange2", "chartreuse3", "orangered1", 
"chartreuse3")

Answer 1

首先，您应该使用 map_data 为 ggplot 创建一个格式良好的数据集，其中包含来自图书馆地图的地图。在这种情况下，您的地图上不会出现这些白点。
当您根据map 函数中的多边形顺序定义颜色顺序时，我创建了一个与map_data 左连接的表格。

# Get polygon order from map
map_france <- map(database="france", fill=TRUE)

# Create a dataframe with department and corresponding colors
names_col <- data.frame(
  region = map_france$names,
  col_dpt = c("yellowgreen", "yellowgreen", "yellowgreen", "yellowgreen", 
              "gold1", "sienna3", "yellowgreen", "yellowgreen", "sienna3", 
              "gold1", "gold1", "gold1", "sienna3", "sienna3", "gold1", "dodgerblue2", 
              "dodgerblue2", "dodgerblue2", "gold1", "dodgerblue2", "sienna3", 
              "dodgerblue2", "burlywood2", "dodgerblue2", "palevioletred4", 
              "dodgerblue2", "palevioletred4", "dodgerblue2", "palevioletred4", 
              "palevioletred4", "gold1", "palevioletred4", "gold1", "darkorchid4", 
              "gold1", "darkorchid4", "palevioletred4", "green4", "cyan4", 
              "gold1", "palevioletred4", "burlywood2", "green4", "green4", 
              "cyan4", "darkorchid4", "green4", "burlywood2", "palevioletred4", 
              "burlywood2", "green4", "green4", "palevioletred4", "palevioletred4", 
              "palevioletred4", "green4", "burlywood2", "olivedrab2", "green4", 
              "olivedrab2", "darkorchid4", "darkorchid4", "cyan4", "darkorchid4", 
              "cyan4", "cyan4", "olivedrab2", "olivedrab2", "olivedrab2", "cyan4", 
              "cyan4", "olivedrab2", "cyan4", "olivedrab2", "olivedrab2", "cyan4", 
              "cyan4", "olivedrab2", "olivedrab2", "olivedrab2", "cyan4", "cyan4", 
              "cyan4", "cyan4", "orange2", "orangered1", "orangered1", "orangered1", 
              "olivedrab2", "orange2", "olivedrab2", "orangered1", "orange2", 
              "orangered1", "orange2", "orange2", "orangered1", "orangered1", 
              "orangered1", "orange2", "orangered1", "orange2", "orangered1", 
              "olivedrab2", "orangered1", "orangered1", "orangered1", "orangered1", 
              "orange2", "orange2", "orange2", "chartreuse3", "orangered1", 
              "chartreuse3")
)

然后你可以将这个数据框加入到map_data创建的数据中，并用ggplot调用颜色向量。

# Get the map in the correct format for ggplot
# And join the correspondance of colors
carte_france <- map_data('france') %>%
  left_join(names_col)

# Plot
ggplot(carte_france, aes(long, lat, group = group)) +
  geom_polygon(col = 1, fill = carte_france$col_dpt) + 
  coord_map(projection = "lambert", 
            parameters = c(lat0 = 41.366005 , lat1 = 51.097523))

为了您的信息，您可以在 IGN 网站 (http://professionnels.ign.fr/geofla) 上下载法国部门的地图，以及该地区的信息。在这种情况下，根据区域名称创建颜色矢量会更容易...