2.0.1 • Published 12 months ago

geokdbush v2.0.1

Weekly downloads
2,563
License
ISC
Repository
github
Last release
12 months ago

geokdbush Node Simply Awesome

A geographic extension for KDBush, the fastest static spatial index for points in JavaScript.

It implements fast nearest neighbors queries for locations on Earth, taking Earth curvature and date line wrapping into account. Inspired by sphere-knn, but uses a different algorithm.

Example

import KDBush from 'kdbush';
import * as geokdbush from 'geokdbush';

const index = new KDBush(points.length);
for (conts {lon, lat} of points) index.add(lon, lat);
index.finish();

const nearestIds = geokdbush.around(index, -119.7051, 34.4363, 1000);

const nearest = nearestIds.map(id => points[id]);

API

geokdbush.around(index, longitude, latitude, maxResults, maxDistance, filterFn)

Returns an array of the closest points from a given location in order of increasing distance.

  • index: kdbush index.
  • longitude: query point longitude.
  • latitude: query point latitude.
  • maxResults: (optional) maximum number of points to return (Infinity by default).
  • maxDistance: (optional) maximum distance in kilometers to search within (Infinity by default).
  • filterFn: (optional) a function to filter the results with.

geokdbush.distance(longitude1, latitude1, longitude2, latitude2)

Returns great circle distance between two locations in kilometers.

Performance

This library is incredibly fast. The results below were obtained with npm run bench (Node v20, Macbook Pro 2020 M1 Pro).

benchmarkgeokdbushsphere-knnnaive
index 138398 points57.6ms408msn/a
query 1000 closest1.6ms1.8ms72ms
query 50000 closest14.7ms91.5ms72ms
query all 13839833.7ms500ms72ms
1000 queries of 124.7ms27.5ms11.1s