| borders {ggplot2} | R Documentation |
This is a quick and dirty way to get map data (from the maps package) on to your plot. This is a good place to start if you need some crude reference lines, but you'll typically want something more sophisticated for communication graphics.
borders(database = "world", regions = ".", fill = NA, colour = "grey50", xlim = NULL, ylim = NULL, ...)
database |
map data, see |
regions |
map region |
fill |
fill colour |
colour |
border colour |
xlim, ylim |
latitudinal and logitudinal range for extracting map
polygons, see |
... |
other arguments passed onto |
if (require("maps")) {
ia <- map_data("county", "iowa")
mid_range <- function(x) mean(range(x))
seats <- plyr::ddply(ia, "subregion", plyr::colwise(mid_range, c("lat", "long")))
ggplot(ia, aes(long, lat)) +
geom_polygon(aes(group = group), fill = NA, colour = "grey60") +
geom_text(aes(label = subregion), data = seats, size = 2, angle = 45)
data(us.cities)
capitals <- subset(us.cities, capital == 2)
ggplot(capitals, aes(long, lat)) +
borders("state") +
geom_point(aes(size = pop)) +
scale_size_area() +
coord_quickmap()
# Same map, with some world context
ggplot(capitals, aes(long, lat)) +
borders("world", xlim = c(-130, -60), ylim = c(20, 50)) +
geom_point(aes(size = pop)) +
scale_size_area() +
coord_quickmap()
}