Map borders: annotation_borders

Mix.install([
  {:giggly, path: Path.join(__DIR__, "..")},
  {:kino, "~> 0.19"}
  ])

About this notebook

This notebook follows the examples on ggplot2's reference page for annotation_borders(), which covers borders() too, in the order the page gives them. Each example shows ggplot2's code first and then Giggly's. An example Giggly cannot draw yet keeps its ggplot2 code and names what it is waiting for, so the page is also a list of what remains.

annotation_borders() is a quick way to put map data from the maps package onto a plot: a layer of polygons outlining the world's countries, by default, or another of the package's maps, such as the US states, to give rough reference lines to data placed by longitude and latitude. Its xlim and ylim pick the part of the map to take. borders() is its old name, now deprecated. Giggly has none of it yet.

State capitals

if (require("maps")) {
data(us.cities)
capitals <- subset(us.cities, capital == 2)
ggplot(capitals, aes(long, lat)) +
  annotation_borders("state") +
  geom_point(aes(size = pop)) +
  scale_size_area() +
  coord_quickmap()
}

require() runs each example only when the maps package is installed; capital == 2 picks the state capitals from its table of US cities.

Not in Giggly yet: map data from the maps package, annotation_borders() and coord_quickmap().

The world around them

if (require("maps")) {
# Same map, with some world context
ggplot(capitals, aes(long, lat)) +
  annotation_borders("world", xlim = c(-130, -60), ylim = c(20, 50)) +
  geom_point(aes(size = pop)) +
  scale_size_area() +
  coord_quickmap()
}

Not in Giggly yet: map data from the maps package, annotation_borders() and its xlim and ylim options, and coord_quickmap().