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}
0.158276 Quadrangle((x: 0.0 m, y: 0.0 m), ..., (x: 0.0 m, y: 1.0 m))
0.287471 Quadrangle((x: 1.0 m, y: 0.0 m), ..., (x: 1.0 m, y: 1.0 m))
0.340293 Quadrangle((x: 2.0 m, y: 0.0 m), ..., (x: 2.0 m, y: 1.0 m))
0.362948 Quadrangle((x: 3.0 m, y: 0.0 m), ..., (x: 3.0 m, y: 1.0 m))
0.241417 Quadrangle((x: 4.0 m, y: 0.0 m), ..., (x: 4.0 m, y: 1.0 m))
0.198794 Quadrangle((x: 5.0 m, y: 0.0 m), ..., (x: 5.0 m, y: 1.0 m))
0.412215 Quadrangle((x: 6.0 m, y: 0.0 m), ..., (x: 6.0 m, y: 1.0 m))
0.335503 Quadrangle((x: 7.0 m, y: 0.0 m), ..., (x: 7.0 m, y: 1.0 m))
0.321616 Quadrangle((x: 8.0 m, y: 0.0 m), ..., (x: 8.0 m, y: 1.0 m))
0.899035 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}
0.158276 Quadrangle((x: 10.0 m, y: 2.4384 m), ..., (x: 10.0 m, y: 3.4384 m))
0.287471 Quadrangle((x: 11.0 m, y: 2.4384 m), ..., (x: 11.0 m, y: 3.4384 m))
0.340293 Quadrangle((x: 12.0 m, y: 2.4384 m), ..., (x: 12.0 m, y: 3.4384 m))
0.362948 Quadrangle((x: 13.0 m, y: 2.4384 m), ..., (x: 13.0 m, y: 3.4384 m))
0.241417 Quadrangle((x: 14.0 m, y: 2.4384 m), ..., (x: 14.0 m, y: 3.4384 m))
0.198794 Quadrangle((x: 15.0 m, y: 2.4384 m), ..., (x: 15.0 m, y: 3.4384 m))
0.412215 Quadrangle((x: 16.0 m, y: 2.4384 m), ..., (x: 16.0 m, y: 3.4384 m))
0.335503 Quadrangle((x: 17.0 m, y: 2.4384 m), ..., (x: 17.0 m, y: 3.4384 m))
0.321616 Quadrangle((x: 18.0 m, y: 2.4384 m), ..., (x: 18.0 m, y: 3.4384 m))
0.899035 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}
0.158276 Quadrangle((ρ: 0.0 m, ϕ: 0.0 rad), ..., (ρ: 1.0 m, ϕ: 1.5708 rad))
0.287471 Quadrangle((ρ: 1.0 m, ϕ: 0.0 rad), ..., (ρ: 1.41421 m, ϕ: 0.785398 rad))
0.340293 Quadrangle((ρ: 2.0 m, ϕ: 0.0 rad), ..., (ρ: 2.23607 m, ϕ: 0.463648 rad))
0.362948 Quadrangle((ρ: 3.0 m, ϕ: 0.0 rad), ..., (ρ: 3.16228 m, ϕ: 0.321751 rad))
0.241417 Quadrangle((ρ: 4.0 m, ϕ: 0.0 rad), ..., (ρ: 4.12311 m, ϕ: 0.244979 rad))
0.198794 Quadrangle((ρ: 5.0 m, ϕ: 0.0 rad), ..., (ρ: 5.09902 m, ϕ: 0.197396 rad))
0.412215 Quadrangle((ρ: 6.0 m, ϕ: 0.0 rad), ..., (ρ: 6.08276 m, ϕ: 0.165149 rad))
0.335503 Quadrangle((ρ: 7.0 m, ϕ: 0.0 rad), ..., (ρ: 7.07107 m, ϕ: 0.141897 rad))
0.321616 Quadrangle((ρ: 8.0 m, ϕ: 0.0 rad), ..., (ρ: 8.06226 m, ϕ: 0.124355 rad))
0.899035 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)