Geohash

Geohash is a latitude/longitude encoding system invented by Gustavo Niemeyer when writing the web service at geohash.org, and put into the public domain. Geohashes offer properties like arbitrary precision, similar prefixes for nearby positions, and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision).

For more information, see: * the Wikipedia article on geohash * an interactive JavaScript example of geohash

Features

Requirements

How to use

GeoHash is very easy to use (and fast) because it's written in C with Ruby bindings.

““ruby require 'geohash'

GeoHash.decode('f77') => [63.98438, -73.82813]

GeoHash.encode(39.51, -76.24) => “dr1bc0edrj”

# Decode a geohash to a bounding box decode_bbox('dqcw4') => [39.0234375, -76.552734375], [39.0673828125, -76.5087890625]] ““

You can encode or decode to an arbitrary level of precision: * Encode latitude and longitude to a geohash with precision digits: encode(lat, lon, precision=10) * Decode a geohash to a latitude and longitude with decimals digits: decode(geohash, decimals=5)

To Develop

1) Install gem dependencies: bundle install 2) If using MRI, compile the C extension: bundle exec rake compile (if you're using JRuby, this step is unnecessary) 3) Run tests: bundle exec rake test

Credits