topic Re: centroid of the polygon in ArcGIS JavaScript Maps SDK Questions

centroid of the polygon

nidhiarora — Wed, 30 Mar 2011 13:48:00 GMT

Hi,
I want to calculate the centroid of the polygon . I tried using Polygon.getExtent().getCenter( ) , but this fn does not return the true center , for example , if the polygon is C shaped.
Any thoughts in this aspect will be appreciated.

Regards,
Nidhi.

Re: centroid of the polygon

HemingZhu — Tue, 05 Apr 2011 20:23:18 GMT

Hi,
I want to calculate the centroid of the polygon . I tried using Polygon.getExtent().getCenter( ) , but this fn does not return the true center , for example , if the polygon is C shaped.
Any thoughts in this aspect will be appreciated.

Regards,
Nidhi.

If the polygon is the result of a task(find, query, identify) on a map/feature service, you could add two fields (x, y) on the polygon layer and populate centroid's x and y using calculate geometry on ArcMap. So when you got the polygon, you could fetch x and y using graphic attributes["x"] and attributes["y"]. If the polygon is the result of a drawing, sorry the current JS api esri.Geometry doesn't have such method as getTrueCentroid. In this case, you might want to create a samll python script as a gp service to calculate centroid of the polyon. Because in Arcpy, Geometry does have a method like trueCentroid(or something like that-can't remember exactly). Another thought: A polyon locator will return centroid point as a result...

Re: centroid of the polygon

nidhiarora — Wed, 06 Apr 2011 19:52:28 GMT

thnx a lot for your inputs. I ll try the GP service.

Re: centroid of the polygon

BryanBaker — Wed, 10 Aug 2011 21:13:59 GMT

This is a little late, but you might find the GeometryService.labelPoints() method useful here. It will return a point that is guaranteed to be within the polygon. It may not be the literal centroid, but it sounds like you're more concerned about the point being within the polygon.

http://help.arcgis.com/en/webapi/javascript/arcgis/help/jsapi/geometryservice.htm#labelPoints

Re: centroid of the polygon

El_BoukfaouiReda — Mon, 12 May 2014 10:43:18 GMT

Hi Everyone,

I am aiming to consume a Public Building Plot areas Map service through ArcMap and generate/export the plots centroids to a feature class to another location. Is there any geoprocessing tool/service able to perform this on a Map service?

Ref.
There is this python script that calculates the centroids of polygon feature classes but only locally :
Calculate centroids (http://resources.arcgis.com/en/help/main/10.1/index.html#//00170000004m000000)

Please Help !