@turf/tin

What is @turf/tin?

@turf/tin is a module of the Turf.js library that allows you to create a Triangulated Irregular Network (TIN) from a set of points. TINs are used in geographic information systems (GIS) to represent a surface. This package is particularly useful for spatial analysis and geospatial data visualization.

What are @turf/tin's main functionalities?

Create TIN from Points

This feature allows you to create a TIN from a set of points. Each point can have properties such as elevation, which can be used to create the TIN. The code sample demonstrates how to create a TIN from three points with elevation properties.

const turf = require('@turf/tin');
const points = turf.featureCollection([
  turf.point([0, 0], {elevation: 10}),
  turf.point([10, 10], {elevation: 20}),
  turf.point([20, 20], {elevation: 30})
]);
const tin = turf.tin(points, 'elevation');
console.log(JSON.stringify(tin));

Other packages similar to @turf/tin

d3-delaunay

d3-delaunay is a D3 module that provides fast algorithms for computing Delaunay triangulations and Voronoi diagrams. It is similar to @turf/tin in that it can be used to create triangulated networks from a set of points. However, d3-delaunay is more focused on performance and is often used in data visualization contexts.

earcut

earcut is a fast, robust polygon triangulation library. While it is not specifically designed for geospatial data, it can be used to triangulate polygons, which is a similar operation to creating a TIN. earcut is known for its speed and simplicity.

triangulate

triangulate is a simple library for triangulating 2D polygons. It is similar to @turf/tin in that it can be used to create a network of triangles from a set of points. However, it is more general-purpose and not specifically designed for geospatial applications.

README

@turf/tin

tin

Takes a set of points and the name of a z-value property and creates a Triangulated Irregular Network, or a TIN for short, returned as a collection of Polygons. These are often used for developing elevation contour maps or stepped heat visualizations.

This triangulates the points, as well as adds properties called a, b, and c representing the value of the given propertyName at each of the points that represent the corners of the triangle.

Parameters

• points FeatureCollection<Point> input points
• z [String] name of the property from which to pull z values This is optional: if not given, then there will be no extra data added to the derived triangles.

Examples

// generate some random point data
var points = turf.random('points', 30, {
  bbox: [50, 30, 70, 50]
});
//=points
// add a random property to each point between 0 and 9
for (var i = 0; i < points.features.length; i++) {
  points.features[i].properties.z = ~~(Math.random() * 9);
}
var tin = turf.tin(points, 'z')
for (var i = 0; i < tin.features.length; i++) {
  var properties  = tin.features[i].properties;
  // roughly turn the properties of each
  // triangle into a fill color
  // so we can visualize the result
  properties.fill = '#' + properties.a +
    properties.b + properties.c;
}
//=tin

Returns FeatureCollection<Polygon> TIN output

---

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/tin

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

$ npm install @turf/turf