Packages
geo
3.3.7
4.1.0
4.0.1
4.0.0
3.6.0
3.5.1
3.5.0
3.4.3
3.4.2
3.4.1
3.4.0
3.3.8
3.3.7
3.3.5
3.3.4
3.3.3
3.3.2
3.3.1
3.3.0
3.2.0
3.1.0
3.0.0
2.1.0
2.0.0
1.5.0
1.4.1
1.4.0
1.3.1
1.3.0
1.2.1
1.2.0
1.1.2
1.1.1
1.1.0
1.0.6
1.0.5
1.0.4
1.0.3
1.0.2
1.0.1
1.0.0
0.18.0
0.17.0
0.16.1
0.16.0
0.15.2
0.15.1
0.15.0
0.14.0
0.13.0
0.12.0
0.11.2
0.11.1
0.11.0
0.10.1
0.10.0
0.9.3
0.9.2
0.9.1
0.9.0
0.8.0
0.7.2
0.7.1
0.6.1
0.5.1
Encodes and decodes WKB, WKT, and GeoJSON formats.
Current section
Files
Jump to
Current section
Files
lib/geo.ex
defmodule Geo do
@moduledoc """
A collection of GIS functions. Handles conversions to and from WKT, WKB, and GeoJSON for the following geometries:
* Point
* PointZ
* LineString
* LineStringZ
* Polygon
* PolygonZ
* MultiPoint
* MultiPointZ
* MulitLineString
* MulitLineStringZ
* MultiPolygon
* MultiPolygonZ
* GeometryCollection
## Examples
* Encode and decode WKT and EWKT
```elixir
iex(1)> point = Geo.WKT.decode("POINT(30 -90)")
%Geo.Point{ coordinates: {30, -90}, srid: nil}
iex(2)> Geo.WKT.encode(point)
"POINT(30 -90)"
iex(3)> point = Geo.WKT.decode("SRID=4326;POINT(30 -90)")
%Geo.Point{coordinates: {30, -90}, srid: 4326}
```
* Encode and decode WKB and EWKB
```elixir
iex(1)> point = Geo.WKB.decode("0101000000000000000000F03F000000000000F03F")
%Geo.Point{ coordinates: {1.0, 1.0}, srid: nil }
iex(2)> Geo.WKB.encode(point)
"00000000013FF00000000000003FF0000000000000"
iex(3)> point = Geo.WKB.decode("0101000020E61000009EFB613A637B4240CF2C0950D3735EC0")
%Geo.Point{ coordinates: {36.9639657, -121.8097725}, srid: 4326 }
iex(4)> Geo.WKB.encode(point)
"0020000001000010E640427B633A61FB9EC05E73D350092CCF"
```
* Encode and decode GeoJSON
Geo only encodes and decodes maps shaped as GeoJSON. JSON encoding and decoding must
be done before and after.
```elixir
#Examples using Jason as the JSON parser
iex(1)> Geo.JSON.encode(point)
%{ "type" => "Point", "coordinates" => [100.0, 0.0] }
iex(2)> point = Jason.decode!("{ \"type\": \"Point\", \"coordinates\": [100.0, 0.0] }") |> Geo.JSON.decode
%Geo.Point{ coordinates: {100.0, 0.0}, srid: nil }
iex(3)> Geo.JSON.encode(point) |> Jason.encode!
"{\"type\":\"Point\",\"coordinates\":[100.0,0.0]}"
```
"""
@type geometry ::
Geo.Point.t()
| Geo.PointZ.t()
| Geo.PointM.t()
| Geo.PointZM.t()
| Geo.LineString.t()
| Geo.LineStringZ.t()
| Geo.Polygon.t()
| Geo.PolygonZ.t()
| Geo.MultiPoint.t()
| Geo.MultiPointZ.t()
| Geo.MultiLineString.t()
| Geo.MultiLineStringZ.t()
| Geo.MultiPolygon.t()
| Geo.MultiPolygonZ.t()
| Geo.GeometryCollection.t()
@typedoc """
Endianess (byte-order) of the WKB/EWKB representation.
* `:ndr` - little-endian
* `:xdr` - big-endian
"""
@type endian :: :ndr | :xdr
if Application.get_env(:geo, :impl_to_string, true) do
defimpl String.Chars,
for: [
Geo.Point,
Geo.PointZ,
Geo.PointM,
Geo.PointZM,
Geo.LineString,
Geo.LineStringZ,
Geo.Polygon,
Geo.PolygonZ,
Geo.MultiPoint,
Geo.MultiPointZ,
Geo.MultiLineString,
Geo.MultiLineStringZ,
Geo.MultiPolygon,
Geo.MultiPolygonZ,
Geo.GeometryCollection
] do
def to_string(geo) do
Geo.WKT.encode!(geo)
end
end
end
if Code.ensure_loaded?(Jason.Encoder) do
defimpl Jason.Encoder,
for: [
Geo.Point,
Geo.PointZ,
Geo.PointM,
Geo.PointZM,
Geo.LineString,
Geo.LineStringZ,
Geo.Polygon,
Geo.PolygonZ,
Geo.MultiPoint,
Geo.MultiPointZ,
Geo.MultiLineString,
Geo.MultiLineStringZ,
Geo.MultiPolygon,
Geo.MultiPolygonZ,
Geo.GeometryCollection
] do
def encode(value, opts) do
Jason.Encode.map(Geo.JSON.encode!(value), opts)
end
end
end
end