turf-collect

turf-collect

collect

Joins attributes FeatureCollection of polygons with a FeatureCollection of points. Given an inProperty on points and an outProperty for polygons, this finds every point that lies within each polygon, collects the inProperty values from those points, and adds them as an array to outProperty on the polygon.

Parameters

• polygons FeatureCollection<Polygon> polygons with values on which to aggregate
• points FeatureCollection<Point> points to be aggregated
• inProperty string property to be nested from
• outProperty string property to be nested into

Examples

var poly1 = polygon([[[0,0],[10,0],[10,10],[0,10],[0,0]]]);
var poly2 = polygon([[[10,0],[20,10],[20,20],[20,0],[10,0]]]);
var polyFC = featurecollection([poly1, poly2]);
var pt1 = point([5,5], {population: 200});
var pt2 = point([1,3], {population: 600});
var pt3 = point([14,2], {population: 100});
var pt4 = point([13,1], {population: 200});
var pt5 = point([19,7], {population: 300});
var ptFC = featurecollection([pt1, pt2, pt3, pt4, pt5]);
var aggregated = aggregate(polyFC, ptFC, 'population', 'values');

aggregated.features[0].properties.values // => [200, 600]);

Returns FeatureCollection<Polygon> polygons with properties listed based on outField

---

This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.

Installation

Install this module individually:

$ npm install turf-collect

Or install the Turf module that includes it as a function:

$ npm install turf