使用 R 中的光栅包为特定国家的省份自定义颜色

Question

我正在尝试标记（绿色、红色、蓝色）特定国家/地区的每个省份，如下所示：

library(raster)
library(rgeos)
library(ggplot2)
library(dplyr)

iran <- getData("GADM", country = "Iran", level = 1)
map <- fortify(iran)
map$id <- as.integer(map$id)
dat <- data.frame(id = 1:(length(iran@data$NAME_1)),
                  state = iran@data$NAME_1,
                  pr = c(530, -42, 1673, 75, 206, 544, 1490, 118, 75,
                         40, 105, 191, 111, 810, 609, 425, 418, 550, 40, 425, -54, -50,
                         16, 18, 133,425, -30, 241,63, 191,100))
dat <- dat %>% mutate(color_province = case_when(pr <= 50 ~ 'green',
                                                 pr > 150 ~ 'red',
                                                 TRUE ~ 'yellow'))

我想为每个省（使用 'dat' 数据框）设置自定义颜色，如下所示：

> dat
   id                       state   pr color_province
1   1                      Alborz  530            red
2   2                     Ardebil  -42          green
3   3                     Bushehr 1673            red
4   4 Chahar Mahall and Bakhtiari   75         yellow
5   5             East Azarbaijan  206            red
6   6                     Esfahan  544            red
7   7                        Fars 1490            red
8   8                       Gilan  118         yellow
9   9                    Golestan   75         yellow
10 10                     Hamadan   40          green
11 11                   Hormozgan  105         yellow
12 12                        Ilam  191            red
13 13                      Kerman  111         yellow
14 14                  Kermanshah  810            red
15 15                   Khuzestan  609            red
16 16  Kohgiluyeh and Buyer Ahmad  425            red
17 17                   Kordestan  418            red
18 18                    Lorestan  550            red
19 19                     Markazi   40          green
20 20                  Mazandaran  425            red
21 21              North Khorasan  -54          green
22 22                      Qazvin  -50          green
23 23                         Qom   16          green
24 24             Razavi Khorasan   18          green
25 25                      Semnan  133         yellow
26 26      Sistan and Baluchestan  425            red
27 27              South Khorasan  -30          green
28 28                      Tehran  241            red
29 29             West Azarbaijan   63         yellow
30 30                        Yazd  191            red
31 31                      Zanjan  100         yellow

例如'Ardebil'省是绿色，'Zanjan'省是黄色。我使用 'Fill' 参数来设置自定义颜色，这是我的尝试：

map_df <- inner_join(map, dat, by = "id")
centers <- data.frame(gCentroid(iran, byid = TRUE))
centers$state <- dat$state
ggplot() +  
geom_map(data = map_df, map = map_df,
         aes(map_id = id, group = group, 
             x = long, y = lat,
             fill = as.factor(color_province))) +
geom_text(data = centers, aes(label = state, x = x, y = y), size = 3) +
coord_map() +
labs(x = "", y = "", title = "Iran Province") +
scale_fill_manual(values = list(yellow = 'yellow', red = 'red', green = 'green'))

但是不行。根据 'dat' 数据框 'Ardebil' 是 'green' 但它在地图上是红色的。有更好的方法吗？

Answer 1

既然你问了我，我就快速浏览了一下你的代码。您对 id 的假设基本上是错误的。当您使用 fortify() 时，您可能认为 id 是按正常顺序分配的（例如，1 到 n）。但事实并非如此。只是运行 unique(mymap$id)。你会明白我的意思。那么解决方案是什么？当您创建 dat 时，您需要 rownames(iran@data)。完成后，您应该没问题。查看最终图形。

library(raster)
library(rgeos)
library(ggplot2)
library(dplyr)

iran <- getData("GADM", country = "Iran", level = 1)
mymap <- fortify(iran) # This is the hidden cause
mymap$id <- as.integer(mymap$id)

dat <- data.frame(id = rownames(iran@data), # This is what you needed.
                  state = iran@data$NAME_1,
                  pr = c(530,-42,1673,75,206,544,1490,118,75,
                         40,105,191,111,810, 609,425,418,550, 40, 425, -54,-50,
                         16, 18, 133,425, -30, 241,63, 191,100)) %>% 
       mutate(color_province = case_when(pr <= 50 ~ 'green',
                                         pr > 150 ~ 'red',
                                         TRUE ~ 'yellow'))

mydf <- inner_join(mymap, dat, by = "id")
centers <- data.frame(gCentroid(iran, byid = TRUE))
centers$state <- dat$state

ggplot() +
geom_map(data = mydf,
         map = mydf,
         aes(map_id = id, group = group,
             x = long, y = lat,
             fill = as.factor(color_province))) +
geom_text(data = centers,
          aes(label = state, x = x, y = y), size = 3) +
coord_map() +
labs(x = "", y = "", title = "Iran Province") +
scale_fill_manual(values = c("green", "red", "yellow"),
                  name = "Province")

使用 R 中的光栅包为特定国家的省份自定义颜色

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