@turf/transform-scale

transformScale

Scale GeoJSON objects from a given point by a scaling factor e.g. factor=2
would make each object 200% larger.
If a FeatureCollection is provided, the origin point will be calculated
based on each individual feature unless an exact

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* geojson ([GeoJSON][1] | [GeometryCollection][2]) objects to be scaled
* factor [number][3] of scaling, positive values greater than 0. Numbers between 0 and 1 will shrink the geojson, numbers greater than 1 will expand it, a factor of 1 will not change the geojson.
* options [Object][4] Optional parameters (optional, default {})

* options.origin (Corners | [Coord][5]) Point from which the scaling will occur (string options: sw/se/nw/ne/center/centroid) (optional, default 'centroid')
* options.mutate [boolean][6] allows GeoJSON input to be mutated (significant performance improvement if true) (optional, default false)

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``javascript
const poly = turf.polygon([[[0,29],[3.5,29],[2.5,32],[0,29]]]);
const scaledPoly = turf.transformScale(poly, 3);

//addToMap
const addToMap = [poly, scaledPoly];
scaledPoly.properties = {stroke: '#F00', 'stroke-width': 4};
`

Returns ([GeoJSON][1] | [GeometryCollection][2]) scaled GeoJSON

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

[2]: https://tools.ietf.org/html/rfc7946#section-3.1.8

[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number

[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object

[5]: https://tools.ietf.org/html/rfc7946#section-3.1.1

[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean

---

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.

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Install this single module individually:

`sh
$ npm install @turf/transform-scale
`

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

`sh
$ npm install @turf/turf
``