turf-concave
turf concave module
turf.concave(points, maxEdge, units)
Takes a set of Point|points and returns a concave hull polygon.
Internally, this uses turf-tin to generate geometries.
Parameters
| parameter | type | description |
|---|---|---|
points |
FeatureCollection.<Point> | input points |
maxEdge |
Number | the size of an edge necessary for part of the hull to become concave (in miles) |
units |
String | used for maxEdge distance (miles or kilometers) |
Example
var points = {
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.601226, 44.642643]
}
}, {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.591442, 44.651436]
}
}, {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.580799, 44.648749]
}
}, {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.573589, 44.641788]
}
}, {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.587665, 44.64533]
}
}, {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-63.595218, 44.64765]
}
}
]
};
var hull = turf.concave(points, 1, 'miles');
var resultFeatures = points.features.concat(hull);
var result = {
"type": "FeatureCollection",
"features": resultFeatures
};
//=resultReturns Feature.<Polygon>, a concave hull
Installation
Requires nodejs.
$ npm install turf-concaveTests
$ npm test
