@turf/tag

tag

Takes a set of [points][1] and a set of [polygons][2] and/or [multipolygons][3] and performs a spatial join.

$3

* points [FeatureCollection][4]<[Point][1]> input points
* polygons [FeatureCollection][4]<([Polygon][2] | [MultiPolygon][3])> input (multi)polygons
* field [string][5] property in polygons to add to joined {} features
* outField [string][5] property in points in which to store joined property from polygons

$3

``javascript
var pt1 = turf.point([-77, 44]);
var pt2 = turf.point([-77, 38]);
var poly1 = turf.polygon([[
[-81, 41],
[-81, 47],
[-72, 47],
[-72, 41],
[-81, 41]
]], {pop: 3000});
var poly2 = turf.polygon([[
[-81, 35],
[-81, 41],
[-72, 41],
[-72, 35],
[-81, 35]
]], {pop: 1000});

var points = turf.featureCollection([pt1, pt2]);
var polygons = turf.featureCollection([poly1, poly2]);

var tagged = turf.tag(points, polygons, 'pop', 'population');

//addToMap
var addToMap = [tagged, polygons]
`

Returns [FeatureCollection][4]<[Point][1]> points with containingPolyId property containing values from polyId

[1]: https://tools.ietf.org/html/rfc7946#section-3.1.2

[2]: https://tools.ietf.org/html/rfc7946#section-3.1.6

[3]: https://tools.ietf.org/html/rfc7946#section-3.1.7

[4]: https://tools.ietf.org/html/rfc7946#section-3.3

[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String

---

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.

$3

Install this single module individually:

`sh
$ npm install @turf/tag
`

Or install the all-encompassing @turf/turf module that includes all modules as functions:

`sh
$ npm install @turf/turf
``