Code to create a map for the #30DayMapChallenge day 20: population

us_population.R

library(ggplot2)
library(dplyr)
library(tigris)
library(tidycensus)

abbr <- state.abb[-c(2, 11)]
state_dat <- vector("list", length(abbr))
names(state_dat) <- abbr

for (i in seq_len(length(state_dat))) {
  state_dat[[i]] <- get_estimates("county",
    "population",
    geometry = TRUE,
    state = names(state_dat)[[i]]
  )
}

state_pops <- do.call(rbind, state_dat)
state_dens <- filter(state_pops, variable == "DENSITY")

county_line <- counties(abbr, TRUE)

state_dens %>%
  arrange(value) %>%
  mutate(idx = row_number()) %>%
  ggplot() +
  geom_sf(aes(fill = idx), color = NA) +
  geom_sf(data = county_line, 
          fill = NA, 
          color = "#F0F0F0", 
          size = 0.03, 
          alpha = 0.05) +
  scale_fill_gradientn(colors = viridisLite::magma(50)) +
  coord_sf() +
  theme_void() %+replace%
  theme(
    legend.position = "none",
    plot.background = element_rect(fill = "#2c2c2c")
  )

ggsave("20_US_pop.png", width = 17, height = 9, dpi = 600)