geohash_nif v1.0.0 Geohash View Source

Drop in replacement fot the Elixir native Geohash encode/decode library implemented as a NIF

Basic Usage

iex(1)> Geohash.encode(42.6, -5.6, 5)
"ezs42"

iex(1)> Geohash.encode(42.6, -5.6, 11)
"ezs42e44yx9"

iex(1)> Geohash.decode("ezs42")
{42.605, -5.603}

iex(1)> Geohash.neighbors("ezs42")
%{
  "e" => "ezs43",
  "n" => "ezs48",
  "ne" => "ezs49",
  "nw" => "ezefx",
  "s" => "ezs40",
  "se" => "ezs41",
  "sw" => "ezefp",
  "w" => "ezefr"
}

iex(1)> Geohash.adjacent("ezs42","n")
"ezs48"

iex(1)> Geohash.bounds("u4pruydqqv")
%{
  max_lat: 57.649115324020386,
  max_lon: 10.407443046569824,
  min_lat: 57.649109959602356,
  min_lon: 10.407432317733765
}

Link to this section Summary

Functions

adjacent(hash, direction)

Calculate adjacent/2 geohash in ordinal direction ["n","s","e","w"].

bounds(hash)

Calculates bounds for a given geohash

decode(hash)

Decodes given geohash to a coordinate pair

decode_to_bits(hash)

Decodes given geohash to a bitstring

encode(latitude, longitude, precision \\ 11)

Encodes given coordinates to a geohash of length precision

neighbors(hash, opts \\ [keys: :strings])

Calculate adjacent hashes for the 8 touching neighbors/2

Link to this section Functions

adjacent(hash, direction)

Calculate adjacent/2 geohash in ordinal direction ["n","s","e","w"].

Examples

iex> Geohash.adjacent("ezs42","n")
"ezs48"

bounds(hash)

Calculates bounds for a given geohash

Examples

iex> Geohash.bounds("u4pruydqqv")
%{
  min_lon: 10.407432317733765,
  min_lat: 57.649109959602356,
  max_lon: 10.407443046569824,
  max_lat: 57.649115324020386
}

decode(hash)

Decodes given geohash to a coordinate pair

Examples

iex> {_lat, _lng} = Geohash.decode("ezs42")
{42.605, -5.603}

decode_to_bits(hash)

Decodes given geohash to a bitstring

Examples

iex> Geohash.decode_to_bits("ezs42")
<<0b0110111111110000010000010::25>>

encode(latitude, longitude, precision \\ 11)

Encodes given coordinates to a geohash of length precision

Examples

iex> Geohash.encode(42.6, -5.6, 5)
"ezs42"

neighbors(hash, opts \\ [keys: :strings])

Calculate adjacent hashes for the 8 touching neighbors/2

Options

These options are specific to this function

:keys -- controls how keys in objects are decoded. Possible values are:
- :strings (default) - decodes keys as binary strings (compatible mode)
- :atoms - decodes keys as atoms (fast mode)

Examples

iex> Geohash.neighbors("6gkzwgjz")
%{
  "n" => "6gkzwgmb",
  "s" => "6gkzwgjy",
  "e" => "6gkzwgnp",
  "w" => "6gkzwgjx",
  "ne" => "6gkzwgq0",
  "se" => "6gkzwgnn",
  "nw" => "6gkzwgm8",
  "sw" => "6gkzwgjw"
}

iex> Geohash.neighbors("6gkzwgjz", keys: :atoms)
%{
  n: "6gkzwgmb",
  s: "6gkzwgjy",
  e: "6gkzwgnp",
  w: "6gkzwgjx",
  ne: "6gkzwgq0",
  se: "6gkzwgnn",
  nw: "6gkzwgm8",
  sw: "6gkzwgjw"
}