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How can I assign a unique identifier to all areas that intesect each other?


jan
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How can I assign a unique identifier to all areas that intesect each other?

Best answer by geomancer

Something like this should work.

Select_one_from_overlapping

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jan
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  • November 17, 2022

Basically I need to keep one of the intersecting areas, but it seems impossible. The Spatial Relator or Spatial Filter are not able to do this.


geomancer
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  • November 17, 2022
jan wrote:

Basically I need to keep one of the intersecting areas, but it seems impossible. The Spatial Relator or Spatial Filter are not able to do this.

Have you looked at the AreaOnAreaOverlayer?


jan
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geomancer wrote:

Have you looked at the AreaOnAreaOverlayer?

Yes, but I don't see how it helps


geomancer
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  • November 17, 2022
jan wrote:

Basically I need to keep one of the intersecting areas, but it seems impossible. The Spatial Relator or Spatial Filter are not able to do this.

With the AreaOnAreaOverlayer you determine the overlapping polygons. The attribute _overlaps gives the number of polygons that intersect. Optionally you can add the attributes to a list, to see which polygons intersect.

AOAO_DemoIf this is not what you are looking for, maybe you can provide some more information (maybe some sample data) on what you are trying to accomplish.


jan
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  • November 17, 2022

CaptureYes I have similar clusters of overlapping polygons, but how can I choose only one polygon from each cluster? And it should not be chopped!

 


geomancer
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  • November 17, 2022

The results of the AreaOnAreaOverlayer do not have any overlap.


geomancer
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  • November 17, 2022

But I think I misinterpreted your question.

In my example there are 3 overlapping polygons, and you want to keep only one of those?

So how to determine which polygon to keep? Largest area? The polygon with the most southern vertex?


jan
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  • November 17, 2022

Yes that's right and I have lots of these clusters, from which I want to select only one and it does not really matter which one since they are close (within each cluster there are groupings to consider but that's not a problem). If I could somehow assign an ID to each cluster and all polygons in that cluster would get that same ID, it would be easy to drop all duplicate ID:s and get only one polygon in each cluster.

Maybe that would be the way to do it. Dissolve all polygons and then assign each polygon an ID. Then use spatial realtor to assign that ID to all polygons within that,...I guess that should work.

 


geomancer
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  • November 17, 2022

Something like this should work.

Select_one_from_overlapping


jan
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  • November 17, 2022
geomancer wrote:

Something like this should work.

Select_one_from_overlapping

Exactly what I was thinking, thanks!


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