union

Description

Takes input (Multi)Polygon(s) and returns a combined polygon. If the input polygons are not contiguous, this function returns a MultiPolygon feature.

Parameters

Name	Type	Description
features	FeatureCollection<Polygon | MultiPolygon>
options?	Object	Optional Parameters (default {})
options.properties?	Object	Translate Properties to output Feature (default {})
polygon1	Feature<Polygon | MultiPolygon>	input Polygon features

Returns

Feature<Polygon | MultiPolygon> a combined Polygon or MultiPolygon feature, or null if the inputs are empty

Examples

var poly1 = turf.polygon(
  [
    [
      [-82.574787, 35.594087],
      [-82.574787, 35.615581],
      [-82.545261, 35.615581],
      [-82.545261, 35.594087],
      [-82.574787, 35.594087],
    ],
  ],
  { fill: "#0f0" },
);
var poly2 = turf.polygon(
  [
    [
      [-82.560024, 35.585153],
      [-82.560024, 35.602602],
      [-82.52964, 35.602602],
      [-82.52964, 35.585153],
      [-82.560024, 35.585153],
    ],
  ],
  { fill: "#00f" },
);

var union = turf.union(turf.featureCollection([poly1, poly2]));

Installation

$ npm install @turf/union

import { union } from "@turf/union";
const result = union(...);

$ npm install @turf/turf

import * as turf from "@turf/turf";
const result = turf.union(...);