80 lines
2.4 KiB
Markdown
80 lines
2.4 KiB
Markdown
# @turf/tin
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<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
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## tin
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Takes a set of [points][1] and creates a
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[Triangulated Irregular Network][2],
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or a TIN for short, returned as a collection of Polygons. These are often used
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for developing elevation contour maps or stepped heat visualizations.
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If an optional z-value property is provided then it is added as properties called `a`, `b`,
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and `c` representing its value at each of the points that represent the corners of the
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triangle.
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**Parameters**
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- `points` **[FeatureCollection][3]<[Point][4]>** input points
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- `z` **[String][5]?** name of the property from which to pull z values
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This is optional: if not given, then there will be no extra data added to the derived triangles.
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**Examples**
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```javascript
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// generate some random point data
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var points = turf.randomPoint(30, {bbox: [50, 30, 70, 50]});
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// add a random property to each point between 0 and 9
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for (var i = 0; i < points.features.length; i++) {
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points.features[i].properties.z = ~~(Math.random() * 9);
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}
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var tin = turf.tin(points, 'z');
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//addToMap
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var addToMap = [tin, points]
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for (var i = 0; i < tin.features.length; i++) {
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var properties = tin.features[i].properties;
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properties.fill = '#' + properties.a + properties.b + properties.c;
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}
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```
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Returns **[FeatureCollection][3]<[Polygon][6]>** TIN output
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[1]: https://tools.ietf.org/html/rfc7946#section-3.1.2
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[2]: http://en.wikipedia.org/wiki/Triangulated_irregular_network
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[3]: https://tools.ietf.org/html/rfc7946#section-3.3
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[4]: https://tools.ietf.org/html/rfc7946#section-3.1.2
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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-3.1.6
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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/tin
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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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