lua-geo

geo location util.

Installation

luarocks install geo --from=http://mah0x211.github.io/rocks/

API

Encode

hash, err = geo.encode( lat:number, lon:number, precision:uint )

returns the geohash encoded string from specified arguments.

local geo = require('geo');
local precision = 16;
local lat = 35.673343;
local lon = 139.710388;
local hash = geo.encode( lat, lon, precision );

print( hash ); -- 'xn76gnjurcpggseg'

Parameters

• lat: number - the latitude value range must be the -90 to 90.
• lon: number - the longitude value range must be the -180 to 180.
• precision: uint - the hash string length range must be the 1 to 16.

Returns

1. hash: string.
2. err: string.

Decode

tbl, err = geo.decode( geohash:string )

returns table that included of latitude and longitude values from the geohash string.

local inspect = require('util').inspect;
local geo = require('geo');
local hash = 'xn76gnjurcpggseg';
local latlon = geo.decode( hash );

print( inspect( latlon ) );
--[[
{
    lat = 35.673342999935,
    lon = 139.71038800008
}
--]]

Parameters

• geohash: string - geohash encoded string.

Returns

1. latlon: table - { lat = latitude:number, lon = longitude:number }.
2. err: string.