73 lines
2.4 KiB
Markdown
73 lines
2.4 KiB
Markdown
# @turf/ellipse
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<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
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## ellipse
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Takes a [Point][1] and calculates the ellipse polygon given two semi-axes expressed in variable units and steps for precision.
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**Parameters**
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- `center` **[Coord][2]** center point
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- `xSemiAxis` **[number][3]** semi (major) axis of the ellipse along the x-axis
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- `ySemiAxis` **[number][3]** semi (minor) axis of the ellipse along the y-axis
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- `options` **[Object][4]** Optional parameters (optional, default `{}`)
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- `options.angle` **[number][3]** angle of rotation (along the vertical axis), from North in decimal degrees, negative clockwise (optional, default `0`)
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- `options.pivot` **[Coord][2]** point around which the rotation will be performed (optional, default `'origin'`)
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- `options.steps` **[number][3]** number of steps (optional, default `64`)
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- `options.units` **[string][5]** unit of measurement for axes (optional, default `'kilometers'`)
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- `options.properties` **[Object][4]** properties (optional, default `{}`)
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**Examples**
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```javascript
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var center = [-75, 40];
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var xSemiAxis = 5;
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var ySemiAxis = 2;
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var ellipse = turf.ellipse(center, xSemiAxis, ySemiAxis);
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//addToMap
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var addToMap = [turf.point(center), ellipse]
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```
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Returns **[Feature][6]<[Polygon][7]>** ellipse polygon
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[1]: https://tools.ietf.org/html/rfc7946#section-3.1.2
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[2]: https://tools.ietf.org/html/rfc7946#section-3.1.1
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[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
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[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
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[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
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[6]: https://tools.ietf.org/html/rfc7946#section-3.2
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[7]: https://tools.ietf.org/html/rfc7946#section-3.1.6
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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/ellipse
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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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