Can I access the raw coordinates?

Access to the raw coordinates of geometries stored in the geometry column is discouraged. If you make good use of the high-level transforms provided by the framework, you will be more productive.

Rigid motion

Coordinates are often called for when the application requires rigid motion. We provide optimized Translate, Rotate and Scale transforms for that purpose:

data = georef((; z=rand(1000, 1000)))
1000000×2 GeoTable over 1000×1000 CartesianGrid
z geometry
Continuous Quadrangle
[NoUnits] 🖈 Cartesian{NoDatum}
0.794647 Quadrangle((x: 0.0 m, y: 0.0 m), ..., (x: 0.0 m, y: 1.0 m))
0.790374 Quadrangle((x: 1.0 m, y: 0.0 m), ..., (x: 1.0 m, y: 1.0 m))
0.479503 Quadrangle((x: 2.0 m, y: 0.0 m), ..., (x: 2.0 m, y: 1.0 m))
0.00251909 Quadrangle((x: 3.0 m, y: 0.0 m), ..., (x: 3.0 m, y: 1.0 m))
0.073638 Quadrangle((x: 4.0 m, y: 0.0 m), ..., (x: 4.0 m, y: 1.0 m))
0.984294 Quadrangle((x: 5.0 m, y: 0.0 m), ..., (x: 5.0 m, y: 1.0 m))
0.674497 Quadrangle((x: 6.0 m, y: 0.0 m), ..., (x: 6.0 m, y: 1.0 m))
0.872818 Quadrangle((x: 7.0 m, y: 0.0 m), ..., (x: 7.0 m, y: 1.0 m))
0.63316 Quadrangle((x: 8.0 m, y: 0.0 m), ..., (x: 8.0 m, y: 1.0 m))
0.332789 Quadrangle((x: 9.0 m, y: 0.0 m), ..., (x: 9.0 m, y: 1.0 m))
data |> Translate(10u"m", 8u"ft")
1000000×2 GeoTable over 1000×1000 CartesianGrid
z geometry
Continuous Quadrangle
[NoUnits] 🖈 Cartesian{NoDatum}
0.794647 Quadrangle((x: 10.0 m, y: 2.4384 m), ..., (x: 10.0 m, y: 3.4384 m))
0.790374 Quadrangle((x: 11.0 m, y: 2.4384 m), ..., (x: 11.0 m, y: 3.4384 m))
0.479503 Quadrangle((x: 12.0 m, y: 2.4384 m), ..., (x: 12.0 m, y: 3.4384 m))
0.00251909 Quadrangle((x: 13.0 m, y: 2.4384 m), ..., (x: 13.0 m, y: 3.4384 m))
0.073638 Quadrangle((x: 14.0 m, y: 2.4384 m), ..., (x: 14.0 m, y: 3.4384 m))
0.984294 Quadrangle((x: 15.0 m, y: 2.4384 m), ..., (x: 15.0 m, y: 3.4384 m))
0.674497 Quadrangle((x: 16.0 m, y: 2.4384 m), ..., (x: 16.0 m, y: 3.4384 m))
0.872818 Quadrangle((x: 17.0 m, y: 2.4384 m), ..., (x: 17.0 m, y: 3.4384 m))
0.63316 Quadrangle((x: 18.0 m, y: 2.4384 m), ..., (x: 18.0 m, y: 3.4384 m))
0.332789 Quadrangle((x: 19.0 m, y: 2.4384 m), ..., (x: 19.0 m, y: 3.4384 m))

Projections

Map projections are examples of coordinate transforms. The Proj function can be used to "reproject" a GeoTable into a new coordinate reference system (CRS):

data |> Proj(Polar)
1000000×2 GeoTable over 1000×1000 TransformedGrid
z geometry
Continuous Quadrangle
[NoUnits] 🖈 Polar{NoDatum}
0.794647 Quadrangle((ρ: 0.0 m, ϕ: 0.0 rad), ..., (ρ: 1.0 m, ϕ: 1.5708 rad))
0.790374 Quadrangle((ρ: 1.0 m, ϕ: 0.0 rad), ..., (ρ: 1.41421 m, ϕ: 0.785398 rad))
0.479503 Quadrangle((ρ: 2.0 m, ϕ: 0.0 rad), ..., (ρ: 2.23607 m, ϕ: 0.463648 rad))
0.00251909 Quadrangle((ρ: 3.0 m, ϕ: 0.0 rad), ..., (ρ: 3.16228 m, ϕ: 0.321751 rad))
0.073638 Quadrangle((ρ: 4.0 m, ϕ: 0.0 rad), ..., (ρ: 4.12311 m, ϕ: 0.244979 rad))
0.984294 Quadrangle((ρ: 5.0 m, ϕ: 0.0 rad), ..., (ρ: 5.09902 m, ϕ: 0.197396 rad))
0.674497 Quadrangle((ρ: 6.0 m, ϕ: 0.0 rad), ..., (ρ: 6.08276 m, ϕ: 0.165149 rad))
0.872818 Quadrangle((ρ: 7.0 m, ϕ: 0.0 rad), ..., (ρ: 7.07107 m, ϕ: 0.141897 rad))
0.63316 Quadrangle((ρ: 8.0 m, ϕ: 0.0 rad), ..., (ρ: 8.06226 m, ϕ: 0.124355 rad))
0.332789 Quadrangle((ρ: 9.0 m, ϕ: 0.0 rad), ..., (ρ: 9.05539 m, ϕ: 0.110657 rad))

Raw coordinates

If you really need access to the coordinates, use the coords function:

quad = data.geometry[1]
Quadrangle
├─ Point(x: 0.0 m, y: 0.0 m)
├─ Point(x: 1.0 m, y: 0.0 m)
├─ Point(x: 1.0 m, y: 1.0 m)
└─ Point(x: 0.0 m, y: 1.0 m)
point = centroid(quad)
Point with Cartesian{NoDatum} coordinates
├─ x: 0.5 m
└─ y: 0.5 m
coords(point)
Cartesian{NoDatum} coordinates
├─ x: 0.5 m
└─ y: 0.5 m

It returns a CRS object. The type of this object can be retrieved with the crs function, which works with any GeoTable, geospatial Domain or individual Geometry:

crs(data)
Cartesian2D{NoDatum, Quantity{Float64, 𝐋, FreeUnits{(m,), 𝐋, nothing}}} (alias for Cartesian{NoDatum, 2, Quantity{Float64, 𝐋, Unitful.FreeUnits{(m,), 𝐋, nothing}}})

Very often the coordinates are LatLon in degrees. These cannot be used in linear algebra routines. The function to converts any CRS object into a static vector with Cartesian coordinates for algebraic manipulation:

to(Point(LatLon(0, 0)))
Vec(6.378137e6 m, 0.0 m, 0.0 m)