I have this line in python to compute First X coordinates into the Field Calculator from each polyline:


Then, when I inspected the attributes I see this rare thing:


You may see that I have two fields (StartX and InicioX), both with the same Python code, one is a string field and the other a Float one. But the computed VALUE is wrong :(

You can clearly see that "spatially" the features are situated in different positions, but on its computed X Value are the same.

Could someone explain me that?

Does anybody know any other way to compute this X,Y start and end coordinates from lines?

Thanks for your time.

  • Remove the selection and repeat the operation. It may simply be a case of the number of decimals being shown, which can be changed for the field
    – user681
    Jul 29, 2014 at 9:29
  • Removed selection, started a new ArcMap session, tried to export to a new shapefile... But nothing changes.
    – juasmilla
    Jul 29, 2014 at 9:50
  • Is the issue that they are all the same value? Your question is a bit unclear
    – GISHuman
    Jul 29, 2014 at 15:40
  • 2
    Have you run the Check Geometry or Repair Geometry tools?
    – nmpeterson
    Jul 29, 2014 at 16:13
  • As @nmpeterson suggested, there was something wrong with the geometry, just needed to repair. Thanks!
    – juasmilla
    Jul 29, 2014 at 16:17

1 Answer 1


Writing my comment as an answer:

It looks to me like there was an issue with the geometry of the shapefile, so running Repair Geometry should (and did) solve this problem.

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