Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | 1x 2x 2x 1x 1x 1x | /** ****************************************************************************************************
* File: neighbors.js
* Project: geohash
* @author Nick Soggin <iSkore@users.noreply.github.com> on 19-Feb-2019
*******************************************************************************************************/
'use strict';
const neighbor = require( './neighbor' );
/**
* neighbors
* Returns all 8 neighbor cells to specified geohash.
* This algorithm is approximately two times faster than ngeohash.
* Times for 1,000,000 iterations
* | ngeohash | Geohash |
* | 0m3.108s | 0m1.675s |
*
* @param {string} geohash - Geohash neighbors are required of.
* @param {boolean} asObject - to return as an object or array
* @returns {{c,n,ne,e,se,s,sw,w,nw}|array} - surrounding geohashes
* @throws Invalid geohash.
*/
function neighbors( geohash, asObject = false ) {
const [ n, ne, e, se, s, sw, w, nw ] = [
neighbor( geohash, 'n' ),
neighbor( neighbor( geohash, 'n' ), 'e' ),
neighbor( geohash, 'e' ),
neighbor( neighbor( geohash, 's' ), 'e' ),
neighbor( geohash, 's' ),
neighbor( neighbor( geohash, 's' ), 'w' ),
neighbor( geohash, 'w' ),
neighbor( neighbor( geohash, 'n' ), 'w' )
];
if ( asObject ) {
return { c: geohash, n, ne, e, se, s, sw, w, nw };
}
else {
return [ n, ne, e, se, s, sw, w, nw ];
}
}
module.exports = neighbors;
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