coord_map {ggplot2} | R Documentation |
This coordinate system provides the full range of map projections available in the mapproj package.
coord_map(projection = "mercator", ..., orientation = NULL, xlim = NULL, ylim = NULL)
projection |
projection to use, see
|
... |
other arguments passed on to
|
orientation |
projection orientation, which defaults
to |
xlim |
manually specific x limits (in degrees of lontitude) |
ylim |
manually specific y limits (in degrees of latitude) |
This is still experimental, and if you have any advice to offer regarding a better (or more correct) way to do this, please let me know
if (require("maps")) { # Create a lat-long dataframe from the maps package nz <- map_data("nz") nzmap <- ggplot(nz, aes(x=long, y=lat, group=group)) + geom_polygon(fill="white", colour="black") # Use cartesian coordinates nzmap # With default mercator projection nzmap + coord_map() # Other projections nzmap + coord_map("cylindrical") nzmap + coord_map("azequalarea",orientation=c(-36.92,174.6,0)) states <- map_data("state") usamap <- ggplot(states, aes(x=long, y=lat, group=group)) + geom_polygon(fill="white", colour="black") # Use cartesian coordinates usamap # With mercator projection usamap + coord_map() # See ?mapproject for coordinate systems and their parameters usamap + coord_map("gilbert") usamap + coord_map("lagrange") # For most projections, you'll need to set the orientation yourself # as the automatic selection done by mapproject is not available to # ggplot usamap + coord_map("orthographic") usamap + coord_map("stereographic") usamap + coord_map("conic", lat0 = 30) usamap + coord_map("bonne", lat0 = 50) # World map, using geom_path instead of geom_polygon world <- map_data("world") worldmap <- ggplot(world, aes(x=long, y=lat, group=group)) + geom_path() + scale_y_continuous(breaks=(-2:2) * 30) + scale_x_continuous(breaks=(-4:4) * 45) # Orthographic projection with default orientation (looking down at North pole) worldmap + coord_map("ortho") # Looking up up at South Pole worldmap + coord_map("ortho", orientation=c(-90, 0, 0)) # Centered on New York (currently has issues with closing polygons) worldmap + coord_map("ortho", orientation=c(41, -74, 0)) }