@turf/transform-scale

transformScale

Scale a GeoJSON from a given point by a factor of scaling (ex: factor=2 would make the GeoJSON 200% larger). If a FeatureCollection is provided, the origin point will be calculated based on each individual Feature.

Parameters

• geojson GeoJSON GeoJSON to be scaled

• factor number 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 Optional parameters (optional, default {})

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

Examples

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

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

Returns GeoJSON scaled GeoJSON

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/transform-scale

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

$ npm install @turf/turf