MapMakie.jl

Plot on OpenStreetMap using Makie.

using GLMakie, MapMakie, MapMaths, Unitful
f = Figure()
a = MapAxis(
    f[1,1];
    origin = LatLon(1.286770, 103.854307), # Merlion, Singapore
    ticks_coordinate = (EastNorth, u"km"),
    limits = (East.(2e3.*(-1,1)), North.(2e3.*(-1,1))),
)
scatter!(
    a,
    Point2f[(0,0)], # WebMercator coordinates relative to `origin`
    color = :red,
    markersize = 15,
    strokewidth = 6,
)
display(f)
save("/tmp/merlion.png", f)

MapAxis(args...; origin, kwargs...) -> axis::Makie.Axis

Create a new Axis showing OpenStreetMap.

The object returned by this function is a plain Makie.Axis and can be used to plot additional data like any other Axis. The map is shown in MapMaths.WebMercator coordinates shifted by -WebMercator(origin).

All positional arguments and any keyword arguments other than the ones mentioned below are forwarded to Axis().

• origin::MapMaths.Coordinate{2}: Map origin.

  This parameter serves two purposes:

  1. Avoid the loss of precision that would otherwise be incurred for locations at high latitudes and longitudes due to Makie performing most computations in Float32. See also Loss of precision when plotting large floats in Makie and related issues in Makie.jl.
  2. Set the origin for the x- and y-ticks if ticks_coordinate is EastNorth (see ticks_coordinate below).

• ticks_coordinate = WebMercator: The coordinate system in which to show the x- and y-ticks.

  Can be any subtype of MapMaths.Coordinate{2}, or (MapMaths.EastNorth, unit) where unit is either a plain number denoting meters, a Unitful.LengthUnits or a Unitful.Length. EastNorth ticks are shown relative to origin, all other ticks are shown using their global values.

• limits = ((-1,1), (-1,1)): Axis limits.

  Follows the same format as Makie.Axis(), except that any number can also be a MapMaths.EastWestCoordinate or MapMaths.NorthSouthCoordinate as appropriate. East and North limits are applied relative to origin, all other limits are applied as global values.

• tile_provider = TileProviders.OpenStreetMap(): Any tile provider from the TileProviders package.

MapMakie dynamically loads the map tiles required from https://tile.openstreetmap.org/. Users of this package must therefore adhere to OpenStreetMap's Tile Usage Policy. The most-recently used 100 MB of map tiles are cached in memory using LRUCache.jl.