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https://issues.apache.org/jira/browse/MATH-1507?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17007654#comment-17007654
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Gilles Sadowski commented on MATH-1507:
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Upgrade which dependency?  Are you developing a software that will depend on 
"commons-geometry"?
Anyways, this is a question for the "dev" ML.  Please post it there.  Thanks.

> Barycenter of a clockwise SphericalPolygonsSet is incorrect.
> ------------------------------------------------------------
>
>                 Key: MATH-1507
>                 URL: https://issues.apache.org/jira/browse/MATH-1507
>             Project: Commons Math
>          Issue Type: Bug
>    Affects Versions: 3.6.1
>            Reporter: Baljit Singh
>            Priority: Major
>
> Let's say there is a circle on a spherical surface.
>  * The circle center is given by S2Point(theta=-0.6981, phi=0.87266). The 
> radius is irrelevant.
>  * Let's discretize this circle into a polygon with 100 edges. Let's make the 
> orientation {color:#ff0000}clockwise{color}.
>  * Since its a clockwise circle, from symmetry, we know that the barycenter 
> would be around S2Point(theta=2.44346, phi=2.268928), which is just the 
> reverse of the normal vector at the circle center.
>  * Using SphericalPolygonsSet, the calculated barycenter is 
> S2Point(theta=2.4922, phi=0.69889).
>  
> A few things I've already tested:
>  * For counterclockwise, the result is correct.
>  * The perimeter and surface area of the polygon is correct for both 
> counterclockwise and clockwise.
>  * The SphericalPolygonsSet barycenter seems to be a function of the circle 
> radius. From symmetry, we know that there should be no dependence on the 
> circle radius.
>  * The theta is kind of close. However, the phi is off about pi/2.
>  
>  
>  
>  



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