1 读取数据

library(tidyverse)
library(sf)
library(camcorder) # for recording ggplot2 graphics

polling_places <- readr::read_csv("polling_places.csv", show_col_types = FALSE)

2 作图

# 创建一个包含州缩写和州全名的数据框
states <- data.frame(
  state = state.abb, # 州缩写
  state_name = state.name # 州全名
)

pp <- polling_places |>
  count(election_date, state, county_name, location_type) |>
  filter(is.na(location_type)) |>
  left_join(states, by = "state") |>
  mutate(
    state_lower = tolower(state_name),
    state_upper = str_to_upper(county_name)
  )

counties <- map_data("county") |>
  rename(state_lower = region, county_lower = subregion) |>
  st_as_sf(coords = c("long", "lat"), crs = 4326)

counties_sf <- counties |>
  group_by(group) |>
  summarise(
    geometry = st_combine(geometry)
  ) |>
  st_cast("POLYGON")

counties_pp <- counties_sf |>
  left_join(
    counties |>
      distinct(group, state_lower, county_lower),
    by = "group"
  ) |>
  left_join(pp) |>
  filter(!is.na(election_date))

states_sf <- map_data("state") %>%
  st_as_sf(coords = c("long", "lat"), crs = 4326) %>%
  group_by(group) %>%
  summarise(geometry = st_combine(geometry)) %>%
  st_cast("POLYGON")

f1 <- "Outfit"

ggplot() +
  geom_sf(data = states_sf, color = NA) +
  geom_sf(data = counties_pp, aes(fill = n), linewidth = 0.05, color = "white") +
  geom_sf(data = states_sf, linewidth = 0.3, color = "white", fill = NA) +
  colorspace::scale_fill_binned_sequential("BurgYl", guide = guide_colorsteps(show.limits = TRUE, title.position = "top")) +
  coord_sf(crs = st_crs("+proj=laea +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +a=6370997 +b=6370997 +units=m +no_defs")) +
  facet_wrap(vars(election_date), ncol = 2, strip.position = "bottom", labeller = function(x) {
    format(x, "%d %B %Y")
  }) +
theme_void(base_family = f1) +
  theme(
    legend.position.inside = c(0.76, 0.17),
    legend.direction = "horizontal",
    legend.key.width = unit(3, "lines"),
    legend.key.height = unit(0.6, "lines"),
    legend.title = element_text(margin = margin(0, 0, 3, 0), size = 13, face = "bold"),
    legend.text = element_text(size = 11),
    strip.text = element_text(size = 11),
    plot.background = element_rect(fill = "grey99", color = NA)
  )