Is there a way to get the center of the polygon?

[bagusflyer]

Is there a way to get the center of the polygon by using turf-swift?

[Udumft]

Hello, @bagusflyer! Unfortunately there is no API method to do that. But I think it should be as simple as calculating "average" among all of Polygon's coordinates.

[1ec5]

But I think it should be as simple as calculating "average" among all of Polygon's coordinates.

That’s one kind of center, but it only yields reasonable results for convex polygons.

Turf.js has several center- and centroid-related functions that we could port to Swift:

• center is similar to the “average” described above and is available in Java as of Porting TurfMeasurement.center mapbox-java#1150
• centerOfMass
• centroid

The iOS map SDK (until v10) has an MGLPolyline.coordinate property that’s very useful for this purpose. Under the hood, it relies on Polylabel, a C++ implementation of the pole-of-inaccessibility algorithm (equivalent to ST_MaximumInscribedCircle in PostGIS). There are other centroid algorithms, but the pole of inaccessibility algorithm yields very good results overall. Now that iOS map SDK v10 relies on Turf for geometric functionality, it’s going to be more important that Turf provides some sort of centroid functionality equivalent to previous map SDK releases.

/cc @mapbox/maps-ios @mapbox/navigation-ios

[1ec5]

Fixed in #148.