coord-map.r

vcontext("coord-map")

library(maps)

# World map
world_map <- map_data("world")
pworld <- ggplot(world_map, aes(x = long, y = lat, group = group)) +
  geom_polygon()


pworld
save_vtest("no projection")


pworld + coord_map(projection = "mercator")
save_vtest("mercator projection")


pworld + coord_map(projection = "ortho") +
  scale_y_continuous(breaks = (-2:2) * 30) +
  scale_x_continuous(breaks = (-4:4) * 45)
save_vtest("ortho projection, default orientation (centered on north pole)")

pworld + coord_map(projection = "ortho", orientation = c(41, -74 ,0)) +
  scale_y_continuous(breaks = (-2:2) * 30) +
  scale_x_continuous(breaks = (-4:4) * 45)
save_vtest("ortho projection, custom orientation (centered on New York)")


# Need to set limits here so left-most longitude line shows up
pworld + coord_map(projection = "aitoff") +
  scale_y_continuous(breaks = (-2:2) * 30) +
  scale_x_continuous(breaks = (-4:4) * 45, limits = c(-180, 180))
save_vtest("aitoff projection, default orientation")


# This drops half of the world, which probably isn't desirable.
# It might require rethinking about how limits work.
pworld + coord_map(projection = "aitoff", orientation = c(90, 180, 0)) +
  scale_y_continuous(breaks = (-2:2) * 30) +
  scale_x_continuous(breaks = (0:8) * 45, limits = c(0, 360))
save_vtest("aitoff projection, custom orientation (centered on date line)")


# USA state map
states_map <- map_data("state")
pstate <- ggplot(states_map, aes(x = long, y = lat, group = group))

pstate + geom_polygon() + coord_map("mercator")
save_vtest("USA map, mercator projection")

end_vcontext()