geo

Examples

Encode and decode WKT and EWKT:

iex(1)> {:ok, 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:

iex(1)> {:ok, 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.

# Examples using Jason as the JSON parser

iex(1)> Geo.JSON.encode(point)
{:ok, %{ "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!
"{\"coordinates\":[100.0,0.0],\"type\":\"Point\"}"

Examples

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