node-geohash

Geohash library for nodejs.

Install

npm install ngeohash

Usage

var geohash = require('geohash');
sys.puts(geohash.encode(37.8324, 112.5584));
// prints ww8p1r4t8
var latlon = geohash.decode('ww8p1r4t8');
sys.puts(latlon.latitude);
sys.puts(latlon.longitude);

geohash.encode (latitude, longitude, precision=9)

Encode a pair of latitude and longitude into geohash. The third argument is optional, you can specify a length of this hash string, which also affect on the precision of the geohash.

geohash.decode (hashstring)

Decode a hash string into pair of latitude and longitude. A javascript object is returned with key latitude and longitude.

geohash.neighbor (hashstring, direction)

Find neighbor of a geohash string in certain direction. Direction is a two-element array, i.e. [1,0] means north, [-1,-1] means southwest.

geohash.decode_bbox (hashstring)

Decode hashstring into a bound box matches it. Data returned in a four-element array: [minlat, minlon, maxlat, maxlon]

geohash.neighbors (hashstring)

Return neighbors of a geohash string in all 8 directions.

geohash.expand (hashstring)

Return neighbors of a geohash string plus the center geohash string itself, useful for DB queries.

About Geohash

Check Wikipedia for more information.