isabella232 / leaflet-knn

k-next-nearest-neighbor searches for Leaflet

leaflet-knn

Next-nearest neighbor searches with sphere-knn, with a Leaflet-friendly API.

example

var gj = L.geoJson(GEOJSON_DATA);
var nearest = leafletKnn(gj).nearest(L.latLng(38, -78), 5);

using it

wget https://raw.github.com/mapbox/leaflet-knn/master/leaflet-knn.min.js

(or without the .min. if you want more debugging power)

With browserify

npm install leaflet-knn

api

var index = leafletKnn(layer)

Generates a lookup function from an L.geoJson layer object.

API is the same as the sphere-knn API for the lookup function, but with nice handling for l.latLng

index.nearest(point: L.LatLng or [lon, lat], n, max_distance)

Given a point, find the nearest points to it. If the index contains multi-point features, like lines, polygons, and so on, it returns points in those features and can return more than one point in each feature.

• point: L.LatLng or [lon, lat], index, [max points: int], [max distance: number])`
• n: the maximum number of points returned from the search
• max_distance: maximum distance in meters

index.nearestLayer(point: L.LatLng or [lon, lat], n, max_distance)

Like nearest, except multiple matches in the same multi-point feature are collapsed, so the array returned has one result per layer.

• point: L.LatLng or [lon, lat], index, [max points: int], [max distance: number])`
• n: the maximum number of points returned from the search
• max_distance: maximum distance in meters