59 lines
1.8 KiB
Markdown
59 lines
1.8 KiB
Markdown
# @turf/polygon-tangents
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<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
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## polygonTangents
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Finds the tangents of a [(Multi)Polygon][1] from a [Point][2].
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### Parameters
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* `pt` **[Coord][3]** to calculate the tangent points from
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* `polygon` **[Feature][4]<([Polygon][1] | [MultiPolygon][5])>** to get tangents from
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### Examples
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```javascript
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var polygon = turf.polygon([[[11, 0], [22, 4], [31, 0], [31, 11], [21, 15], [11, 11], [11, 0]]]);
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var point = turf.point([61, 5]);
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var tangents = turf.polygonTangents(point, polygon)
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//addToMap
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var addToMap = [tangents, point, polygon];
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```
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Returns **[FeatureCollection][6]<[Point][2]>** Feature Collection containing the two tangent points
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[1]: https://tools.ietf.org/html/rfc7946#section-3.1.6
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[2]: https://tools.ietf.org/html/rfc7946#section-3.1.2
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[3]: https://tools.ietf.org/html/rfc7946#section-3.1.1
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[4]: https://tools.ietf.org/html/rfc7946#section-3.2
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[5]: https://tools.ietf.org/html/rfc7946#section-3.1.7
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[6]: https://tools.ietf.org/html/rfc7946#section-3.3
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<!-- This file is automatically generated. Please don't edit it directly. If you find an error, edit the source file of the module in question (likely index.js or index.ts), and re-run "yarn docs" from the root of the turf project. -->
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---
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This module is part of the [Turfjs project](https://turfjs.org/), an open source module collection dedicated to geographic algorithms. It is maintained in the [Turfjs/turf](https://github.com/Turfjs/turf) repository, where you can create PRs and issues.
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### Installation
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Install this single module individually:
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```sh
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$ npm install @turf/polygon-tangents
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```
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Or install the all-encompassing @turf/turf module that includes all modules as functions:
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```sh
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$ npm install @turf/turf
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```
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