turf.concave() returned undefined at high precision

Currently I’m using the turf.concave method to convert a feature of points to a polygon.

var hull = turf.concave( fc, 1, 'miles' )

Although I can’t make the polygon concave on points lower than 1 mile. If I try:

var hull = turf.concave( fc, 0.001, 'miles' )

hull returns undefined.

Any ideas? I need to get a better accuracy reading here. Thank you!!!

[rowanwins]

Gday @roblav96

So it looks like it is the maxEdge setting that it throwing things out for you http://turfjs.party/#/de35288c26dd7d456ff9

By setting the maxEdge at .001 miles you are basically saying each polygon edge should only be .001miles however your points are not spaced that closely together.

So basically if your points are close together you can set a very small maxEdge however if your points are far apart you need to increase your maxEdge setting.

That’s probably the best I can offer without knowing more about your use case…

Cheers Rowan

[roblav96]

Here are the points for this demo: http://geojson.io/#id=gist:anonymous/165bdfb1b1e396c6dbe7&map=15/42.3369/-71.1686

Here is the code:

turTurfItRealGoooood: function () {
    var features = []
    _.forEach( this.markers, function ( value, index ) {
        var point = turf.point( [ value.point.lng, value.point.lat ] )
        features.push( point )
    } )
    console.log( 'features >', features )

    var fc = turf.featurecollection( features )
    console.log( 'fc >', fc )

    var hull = turf.concave( fc, 0.001, 'miles' )
    console.log( 'hull >', hull )
},

The variable ‘fc’ are the points on the map I posted.