turf tin module
Takes a set of Point|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.
| parameter | type | description |
|---|---|---|
points |
FeatureCollection.<Point> | input points |
propertyName |
String | optional: 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. |
// 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;
}
//=tinReturns FeatureCollection.<Polygon>, TIN output
Requires nodejs.
$ npm install turf-tin$ npm test