libgeohash

A library used for encoding/decoding geohashes.

libgeohash was originally developed by Derek Smith @ simplegeo as a BSD licensed reference implementation for the Public Domain Geohash algorithm invented in 2008 by Gustavo Niemeyer

pylibgeohash has been added under the same license as the original

To use libgeohash just run

cmake .
make

to build and test the python wrapper

   python3 setup.py bdist_wheel
   pip3 install dist/pylibgeohash*

Installation

Linux and Mac users can install the package via pip.

Wheel file available for ubuntu bionic

pip install pylibgeohash

Encode

c

char* hash =  geohash_encode(double lat, double lng, int precision);
<do stuff>
free(hash);

python

import pylibgeohash as geohash
hash = geohash.geohash_encode(lat, lon, precision)

Takes in latitude and longitude with a desired precision and returns the correct hash value. If precision < 1 or precision > 12, a default value of 6 will be used.

Decode

c

GeoCoord coord = geohash_decode(char* hash);
coord.latitude;
coord.longitude;

python

import pylibgeohash as geohash
coord = geohash.geohash_decode("ezs42")
coord["latitude"] 
coord["longitude"]

Produces an allocated GeoCoord structure which contains the latitude and longitude that was decoded from the geohash. A GeoCoord also provides the bounding box for the geohash (north, east, south, west).

Neighbors

c

char** geohash_neighbors(char* hash);
neighbors[0];

python

neighbors = pylibgeohash.neighbors(str_hash)
neighbors[0]

Uses the bounding box declared at hash and calculates the 8 neighboring boxes. An example is show below.

• ezefx ezs48 ezs49
• ezefr ezs42 ezs43
• ezefp ezs40 ezs41

The value returned is an array of char* with length of 8. The neighboring positions of values are shown below with each box representing the index of the array.

• 7 0 1
• 6 * 2
• 5 4 3

Similar works