How do I get a country as a region?

Question

I am trying to color a country map based on level of weather risk in each admin area. I believe this can best be done in R, though my knowledge of R is next to zero.

From this post cannot add labels for country with ggplot, geom_polygon and geom_text, I have been able to run the code and plot a risk map of all countries in Africa. I tried to adapt the code for my purpose as below:

library(sf)
library(ggplot2)

all_districts <- data.frame(region = c("Maseru",
"Butha-Buthe",
"Leribe",
"Berea",
"Mafeteng", 
"Mohale's Hoek", 
"Quthing",
"Qacha's Nek",
"Mokhotlong",
"Thaba-Tseka"),                          
risk = c(4, 4, 2, 1, 2, 4, 1, 3, 1, 2))

table(all_districts$risk)
mapdata_x <- map_data('world') %>% filter(region %in% all_districts$region)
mapdata_x <- mapdata_x %>% left_join(all_districts, by='region')
label_data <- mapdata_x %>% group_by(region) %>% filter(row_number() == 1)

ggplot(mapdata_x, aes (x = long, y = lat, group = group)) +
geom_polygon(aes(fill = factor(risk)), linewidth = 0.25, color = "black") +
scale_fill_manual(values = c("#a6d96a", "#ffffbf", "#fdae61", "#d7191c"),
name = "Risk Level") +
theme(axis.text.x = element_blank(),
axis.text.y = element_blank(),
axis.ticks = element_blank(),
axis.ticks = element_blank(),
axis.title.y = element_blank(),
axis.title.x = element_blank(),
rect = element_blank())+
labs(title = "Weather Risk Levels") +
geom_label_repel(data = label_data,
aes(x = long, y = lat, label = region), size = 3,
max.overlaps = 12)

My code fails on the line

mapdata_x <- map_data('world') %>% filter(region %in% all_districts$region)

Giving the error:

Error in h(simpleError(msg, call)) : 
  error in evaluating the argument 'x' in selecting a method for function '%in%': object 'region' not found.

How do I define this so that I can get Lesotho as a region?, or if there is an alternative way of achieving this.

Answer 1

library(sf); library(sp)
library(dplyr)
library(ggplot2); library(ggrepel)

download.file("https://biogeo.ucdavis.edu/data/diva/adm/LSO_adm.zip",
              "LSO_adm.zip")
unzip("LSO_adm.zip", exdir= "LSO_adm")

mapdata_x <- st_read(dsn="LSO_adm\\LSO_adm1.shp", quiet = TRUE)
all_districts <- data.frame(region = c("Maseru", "Butha-Buthe",
                                       "Leribe", "Berea", 
                                       "Mafeteng", "Mohale's Hoek", 
                                        "Quthing", "Qacha's Nek", 
                                        "Mokhotlong", "Thaba-Tseka"),
                            risk = c(4, 4, 2, 1, 2, 4, 1, 3, 1, 2))

mapdata_x <- mapdata_x %>% left_join(all_districts, by = c("NAME_1" = 'region'))
label_data <-  suppressWarnings(st_centroid(mapdata_x)) %>% 
                bind_cols(., st_coordinates(.))

ggplot() +
  geom_sf(data = mapdata_x, aes(fill = factor(risk))) +
  geom_label_repel(data = label_data, aes(x = X, y = Y, label = NAME_1), 
                   size = 3, max.overlaps = 12) +
  labs(title = "Weather Risk Levels") +
  scale_fill_manual(name = "Risk Level", 
                    values = c("#a6d96a", "#ffffbf", "#fdae61", "#d7191c")) +
  theme(axis.text = element_blank(),
        axis.ticks = element_blank(),
        axis.title = element_blank(),
        rect = element_blank())

^{Created on 2024-03-29 with reprex v2.0.2}