67 lines
2.3 KiB
Markdown
67 lines
2.3 KiB
Markdown
# @turf/transform-scale
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<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
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## transformScale
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Scale a GeoJSON from a given point by a factor of scaling (ex: factor=2 would make the GeoJSON 200% larger).
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If a FeatureCollection is provided, the origin point will be calculated based on each individual Feature.
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**Parameters**
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- `geojson` **[GeoJSON][1]** GeoJSON to be scaled
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- `factor` **[number][2]** of scaling, positive or negative values greater than 0
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- `options` **[Object][3]** Optional parameters (optional, default `{}`)
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- `options.origin` **([string][4] \| [Coord][5])** Point from which the scaling will occur (string options: sw/se/nw/ne/center/centroid) (optional, default `'centroid'`)
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- `options.mutate` **[boolean][6]** allows GeoJSON input to be mutated (significant performance increase if true) (optional, default `false`)
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**Examples**
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```javascript
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var poly = turf.polygon([[[0,29],[3.5,29],[2.5,32],[0,29]]]);
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var scaledPoly = turf.transformScale(poly, 3);
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//addToMap
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var addToMap = [poly, scaledPoly];
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scaledPoly.properties = {stroke: '#F00', 'stroke-width': 4};
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```
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Returns **[GeoJSON][1]** scaled GeoJSON
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[1]: https://tools.ietf.org/html/rfc7946#section-3
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[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
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[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
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[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
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[5]: https://tools.ietf.org/html/rfc7946#section-3.1.1
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[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
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<!-- This file is automatically generated. Please don't edit it directly:
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if you find an error, edit the source file (likely index.js), and re-run
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./scripts/generate-readmes in the turf project. -->
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---
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This module is part of the [Turfjs project](http://turfjs.org/), an open source
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module collection dedicated to geographic algorithms. It is maintained in the
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[Turfjs/turf](https://github.com/Turfjs/turf) repository, where you can create
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PRs and issues.
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### Installation
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Install this module individually:
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```sh
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$ npm install @turf/transform-scale
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```
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Or install the Turf module that includes it as a function:
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```sh
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$ npm install @turf/turf
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```
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