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Question

Deleting polygons witch have the same coordinates (duplicates)

  • 1 April 2013
  • 5 replies
  • 3 views

Hello, 

I was wondering if this can be done with an operator? Many times, I see polygon shapefiles which have a feature duplicated even 1,000 times (same coordinates).

Let's say that I need a clean shapefile, and I want to get rid of the polygons which are duplicated several times (i am not interested in the attributes..even if they are different for the same geometry, I want to delete them and keep only one)

Is this possible? 

5 replies

Badge +6

Oh my God. I meant which*** not witch! Why can't we edit our post? I cannot understand any reason for this. At least a time frame of 10 minutes for editinf reasons...

Sorry all!

Userlevel 5
Badge +13
Hi,

 

 

There are several ways to do it, I would calculate a CRC on the geometry and test for unique CRC values.

 

Hope this helps.
Userlevel 5
Badge +13
btw for testing unique CRC values I would use the duplicate remover.

 

 

 

Userlevel 5
Hi Robert,

 

 

have you looked at the Matcher? It will allow you to find matching features based on matching geometry, matching attributes, or both.

 

 

If you already have a license for the MRFCleaner transformers (or have a budget for it), the MRF2DCleaner will do the same thing, but with a lot more options and functionality. Very handy in some instances.

 

 

If you want to persue the solution proposed by Itay, take a look at the CRCCalculator. Just be aware that this solution will not give you any leeway in regards of tolerances, though.

 

 

David
Badge +6

Hello,

Thank you all for the assistance! 

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