https://github.com/felt/geo

A collection of GIS functions for Elixir
https://github.com/felt/geo

Last synced: 18 days ago
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A collection of GIS functions for Elixir

• Host: GitHub
• URL: https://github.com/felt/geo
• Owner: felt
• License: mit
• Created: 2014-03-06T02:15:05.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2024-04-15T14:01:28.000Z (7 months ago)
• Last Synced: 2024-04-26T13:56:40.095Z (7 months ago)
• Language: Elixir
• Size: 464 KB
• Stars: 606
• Watchers: 22
• Forks: 87
• Open Issues: 12
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# Geo

[![Build Status](https://github.com/felt/geo/actions/workflows/elixir-build-and-test.yml/badge.svg?branch=master)](https://github.com/felt/geo/actions/workflows/elixir-build-and-test.yml)

[![Module Version](https://img.shields.io/hexpm/v/geo.svg)](https://hex.pm/packages/geo)

[![Hex Docs](https://img.shields.io/badge/hex-docs-lightgreen.svg)](https://hexdocs.pm/geo/)

[![Total Download](https://img.shields.io/hexpm/dt/geo.svg)](https://hex.pm/packages/geo)

[![License](https://img.shields.io/hexpm/l/geo.svg)](https://github.com/felt/geo/blob/master/LICENSE)

[![Last Updated](https://img.shields.io/github/last-commit/felt/geo.svg)](https://github.com/felt/geo/commits/master)

A collection of GIS functions. Handles conversions to and from well-known text (WKT), well-known binary (WKB), and GeoJSON for the following geometries:

* Point

* PointZ

* PointM

* PointZM

* LineString

* LineStringZ

* LineStringZM

* Polygon

* PolygonZ

* MultiPoint

* MultiPointZ

* MultiLineString

* MultiLineStringZ

* MultiPolygon

* MultiPolygonZ

* GeometryCollection

_Note_: If you are looking for the Postgrex PostGIS extension, check out [geo_postgis](https://github.com/felt/geo_postgis).

_Note_: If you are looking to do geospatial calculations in memory with Geo's structs, check out [topo](https://github.com/pkinney/topo).

```elixir

defp deps do

  [

    {:geo, "~> 3.6"}

  ]

end

```

## Examples

Encode and decode WKT and EWKT:

```elixir

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:

```elixir

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.

```elixir

# 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\"}"

```

## Copyright and License

Copyright (c) 2014 Bryan Joseph

Released under the MIT License, which can be found in the repository in [`LICENSE`](https://github.com/felt/geo/blob/master/LICENSE.md).