geohash

This package is based on latlon-geohash by Chris Veness adapted and refactored for TypeScript applications. Original code is under MIT License.

Functions to convert a geohash to/from a latitude/longitude point, and to determine bounds of a geohash cell and find neighbours of a geohash.

API

• Geohash.encode(lat, lon, [precision]): encode latitude/longitude point to geohash of given precision (number of characters in resulting geohash); if precision is not specified, it is inferred from precision of latitude/longitude values.
• Geohash.decode(geohash): return { lat, lon } of centre of given geohash, to appropriate precision.
• Geohash.bounds(geohash): return { sw, ne } bounds of given geohash.
• Geohash.adjacent(geohash, direction): return adjacent cell to given geohash in specified direction (N/S/E/W).
• Geohash.neighbours(geohash): return all 8 adjacent cells (n/ne/e/se/s/sw/w/nw) to given geohash.

Note to obtain neighbours as an array, you can use

const neighboursObj = Geohash.neighbours(geohash);
const neighboursArr = Object.keys(neighboursObj).map(n => neighboursObj[n]);

The parent of a geocode is simply geocode.slice(0, -1).

If you want the geohash converted from Base32 to Base4, you can e.g.:

parseInt(Geohash.encode(52.20, 0.12, 6), 32).toString(4);

Usage

Geohash can be used in a Node.js app from npm:

$ npm install node-geohash 
> import Geohash from 'node-geohash';
> const geohash = Geohash.encode(52.20, 0.12, 6);
> console.assert(geohash == 'u120fw');
> const latlon = Geohash.decode('u120fw');
> console.assert(JSON.stringify(latlon) == '{"lat":52.1988,"lon":0.115}');