turf-sum

turf sum module

turf.sum(polygons, points, inField, outField)

Calculates the sum of a field for Point features within a set of Polygon features.

Parameters

parameter	type	description
polygons	FeatureCollection	a FeatureCollection of Polygon features
points	FeatureCollection	a FeatureCollection of Point features
inField	String	the field in input data to analyze
outField	String	the field in which to store results

Example

var polygons = turf.featurecollection([
  turf.polygon([[
    [-87.990188, 43.026486],
    [-87.990188, 43.062115],
    [-87.913284, 43.062115],
    [-87.913284, 43.026486],
    [-87.990188, 43.026486]
  ]]),
  turf.polygon([[
    [-87.973709, 42.962452],
    [-87.973709, 43.014689],
    [-87.904014, 43.014689],
    [-87.904014, 42.962452],
    [-87.973709, 42.962452]
  ]])
]);
var points = turf.featurecollection([
  turf.point([-87.974052, 43.049321], {population: 200}),
  turf.point([-87.957229, 43.037277], {population: 600}),
  turf.point([-87.931137, 43.048568], {population: 100}),
  turf.point([-87.963409, 42.99611], {population: 200}),
  turf.point([-87.94178, 42.974762], {population: 300})
]);
 
var aggregated = turf.sum(
  polygons, points, 'population', 'sum');
 
var result = turf.featurecollection(
  points.features.concat(aggregated.features));
 
//=result

Installation

Requires nodejs.

$ npm install turf-sum

Tests

$ npm test