topic REST Query: input ring selecting points in ArcGIS JavaScript Maps SDK Questions

REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 18:30:45 GMT

I'm getting odd result attempting to select points by an input ring geometry. It's actually selecting all of the points that fall outside of the input ring!

I'm missing the obvious here.

Re: REST Query: input ring selecting points

RobertScheitlin__GISP — Fri, 18 Oct 2019 18:34:48 GMT

James,

That sounds like your point order for the ring is counter-clockwise then.

Re: REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 18:51:32 GMT

Yes that sounds like the issue. I will look to see if there's any sorting problems I am having.

Re: REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 19:12:32 GMT

I'm not sure how best to handle this. If I query an existing map service and get a ring, is there any way to guarantee its point order?

Re: REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 19:27:52 GMT

Robert -- I think I will take this over to the Python forum section. You've identified the issue and I've marked your post correct answer.

Thanks!

Re: REST Query: input ring selecting points

RobertScheitlin__GISP — Fri, 18 Oct 2019 19:30:28 GMT

James,

that is strange that you are querying a ring that is counter-clockwise. In the JS API you can use the Polygon class to test for clockwise and then use Geometry service simplify to ensure it is. But the easier way then the Geometry service is to just use the JS Array reverse method.

Re: REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 19:43:06 GMT

Ah. Maybe I can just run the ring thru the Geometry service after I get it. This is a python implementation but it's just another REST request.

Re: REST Query: input ring selecting points

JamesCrandall — Fri, 18 Oct 2019 19:52:20 GMT

I tried running the ring into the Geometry service simplify task and it didn't seem to format the point order correctly.