make_map2.R

library(geojsonio)
library(here)
library(broom)

reload <- FALSE
if(reload) {
  spdf <- geojson_read(
    x = here("unsw_map", "worldgeo.json"),
    what = "sp"
  )
}

spdf_fortified <- tidy(spdf, region = "admin")
spdf_other <- tibble(
  id = spdf$admin,
  pop = spdf$pop_est
)

spdf_all <- full_join(spdf_fortified, spdf_other)

# Now I can plot this shape easily as described before:
pic <- ggplot() +
  geom_polygon(
    data = spdf_fortified,
    mapping = aes(
      x = long,
      y = lat,
      group = group,
      color = pop,
      fill = pop
    ),
    show.legend = FALSE
  ) +
  theme_void() +
  coord_map()

plot(pic)