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Extracting overlapped polygons

  • July 20, 2018
  • 7 replies
  • 13 views

fmeuser_gc
Contributor
Forum|alt.badge.img+9

Hello,

I have 2 polygons overlapped. I'd like to split polygons into two A, B. Have tried with DonutBuilder and DonutHoleExtractor transformers, but it still looks overlapped

 

Please advise how to split the polygons.

 

Original Polygon

Output Polygon after using DonutBuilder / DonutHoleExtractor:

In Fig-1, the polygons are overlapped.

In Fig-2, here the polygon is highlighted when we click on it.

Tagging @takashi, @david_r, @DaveAtSafe

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7 replies

Forum|alt.badge.img+2
  • 1891 replies
  • July 20, 2018

The DonutBuilder has a parameter Drop Holes: Yes|No. Try using Drop Holes = Yes. However, it does look like your areas touch, in which cae you don't really have a donut. You might try AreaOnAreaOverlayer instead.


fmeuser_gc
Contributor
Forum|alt.badge.img+9
  • Author
  • Contributor
  • 81 replies
  • July 21, 2018
@MarkAtSafe

Have tried with DonutBuilder with Drop Holes and hidden polygon is being dropped. However I need both polygons with no overlaps.


takashi
Celebrity
  • 7843 replies
  • July 22, 2018

If the DonutBuilder can create a donut from the polygons, you can just set No to the Drop Holes parameter to keep both the donut and the hole. You should not use the DonutHoleExtractor.


fmeuser_gc
Contributor
Forum|alt.badge.img+9
  • Author
  • Contributor
  • 81 replies
  • July 23, 2018

If the DonutBuilder can create a donut from the polygons, you can just set No to the Drop Holes parameter to keep both the donut and the hole. You should not use the DonutHoleExtractor.

@takashi - DropHoles parameter was set to NO, but the polygons still doesn't split.

 


Forum|alt.badge.img+2
  • 1891 replies
  • July 23, 2018

If the DonutBuilder can create a donut from the polygons, you can just set No to the Drop Holes parameter to keep both the donut and the hole. You should not use the DonutHoleExtractor.

@fmeuser_gc I think you'll have to attach a sample of the data.

 

As I mentioned before, it does look like your area might not be a valid donut - it looks like the hole touches the shell. If you can attach a small sample of the data, members of the community can take a look and try and understand why your donuts aren't forming as you expect.

 


ebygomm
Influencer
Forum|alt.badge.img+44
  • Influencer
  • 3430 replies
  • July 24, 2018
@fmeuser_gc I think you'll have to attach a sample of the data.

 

As I mentioned before, it does look like your area might not be a valid donut - it looks like the hole touches the shell. If you can attach a small sample of the data, members of the community can take a look and try and understand why your donuts aren't forming as you expect.

 

The donutbuilder will still create a donut if the hole only touches at a single point of the shell (albeit one that will fail validation for self interesections). Starts to do funky stuff if there is an overlap (in 2017 anyway, might have changed in 2018)

 

 


fmeuser_gc
Contributor
Forum|alt.badge.img+9
  • Author
  • Contributor
  • 81 replies
  • July 26, 2018
@fmeuser_gc I think you'll have to attach a sample of the data.

 

As I mentioned before, it does look like your area might not be a valid donut - it looks like the hole touches the shell. If you can attach a small sample of the data, members of the community can take a look and try and understand why your donuts aren't forming as you expect.

 

@MarkAtSafe - Is there a way to attach file > 1 MB? I couldn't attach .SHP file due to larger size.