https://github.com/evuez/geohax

Geohash encoding and decoding for Elixir.
https://github.com/evuez/geohax

geohash geolocation hacktoberfest

Last synced: about 2 months ago
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Geohash encoding and decoding for Elixir.

• Host: GitHub
• URL: https://github.com/evuez/geohax
• Owner: evuez
• License: mit
• Created: 2016-10-20T14:51:49.000Z (about 8 years ago)
• Default Branch: main
• Last Pushed: 2024-05-12T17:58:53.000Z (8 months ago)
• Last Synced: 2024-10-19T17:30:01.765Z (3 months ago)
• Topics: geohash, geolocation, hacktoberfest
• Language: Elixir
• Homepage: https://hex.pm/packages/geohax
• Size: 28.3 KB
• Stars: 12
• Watchers: 2
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Geohax

[![Hex.pm](https://img.shields.io/hexpm/v/geohax.svg)](https://hex.pm/packages/geohax)

[![Build Status](https://travis-ci.org/evuez/geohax.svg?branch=main)](https://travis-ci.org/evuez/geohax)

[![Inline docs](http://inch-ci.org/github/evuez/geohax.svg)](http://inch-ci.org/github/evuez/geohax)

[![Hex.pm](https://img.shields.io/hexpm/dt/geohax.svg)](https://hex.pm/packages/geohax)

Geohash encoding and decoding for Elixir.

**Note**: This project doesn't receive many updates mainly because its API is fairly small. **I'm still actively maintaining it.**

## Ordering of longitude and latitude

*Every* function in `Geohax` use the `longitude,latitude` ordering; make sure not to invert these!

Both [Redis](https://redis.io/commands/geoadd) and [PostGIS](https://postgis.net/docs/ST_MakePoint.html) use this same ordering, but if you feel strongly about that and would prefer to use `latitude,longitude` instead, you can simply create a new module that does this for you:

```elixir

defmodule MyGeohash do

  def decode(geohash) do

    {lon, lat} = Geohax.decode(geohash)

    {lat, lon}

  end

  def encode(latitude, longitude, precision \\ 12),

    do: Geohax.encode(longitude, latitude, precision)

  defdelegate neighbor(geohash, direction), to: Geohax

  defdelegate neighbors(geohash), to: Geohax

  defdelegate within(min, max, precision \\ 5), to: Geohax

end

```

## Usage

### Encoding and decoding

```elixir

iex> Geohax.encode(-132.83, -38.1033, 6)

"311x1r"

iex> Geohax.decode("311x1r")

{-132.83, -38.1033}

```

Note that the format for coordinates is `{longitude, latitude}`.

### Finding neighbors

```elixir

iex> Geohax.neighbors("311x1r")

%{north: "311x32", south: "311x1q", east: "311x1x", west: "311x1p"}

iex> Geohax.neighbor("311x1r", :north)

"311x32"

```

### Calculating geoashes within an envelope

```elixir

iex> Geohax.within({52.291725, 16.731831}, {52.508736, 17.071703})

["u37ck", "u37cm", "u37cq", "u37cr", "u3k12", "u3k13", "u3k16", "u3k17", "u3k1k", "u37cs", "u37ct", "u37cw", "u37cx", "u3k18", "u3k19", "u3k1d", "u3k1e", "u3k1s", "u37cu", "u37cv", "u37cy", "u37cz", "u3k1b", "u3k1c", "u3k1f", "u3k1g", "u3k1u", "u37fh", "u37fj", "u37fn", "u37fp", "u3k40", "u3k41", "u3k44", "u3k45", "u3k4h", "u37fk", "u37fm", "u37fq", "u37fr", "u3k42", "u3k43", "u3k46", "u3k47", "u3k4k", "u37fs", "u37ft", "u37fw", "u37fx", "u3k48", "u3k49", "u3k4d", "u3k4e", "u3k4s"]

```

## Installation

Add the `:geohax` dependency to your `mix.exs` file:

```elixir

defp deps do

  [{:geohax, "~> 1.0"}]

end

```

Then, run `mix deps.get` to fetch the new dependency.