I'm running arcmap 10.4.1 trying to make a simple outline from a polygon shapefile. Should be a piece of cake, but a small part of the polygon extends off past the dataframe at the default projection. When I reproject with a 180° central meridian to get the entire thing in one piece, arcmap creates a vertical line where the polygon crossed the dataframe by adding extra vertices.

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I can edit these vertices normally such that the line should disappear, but as soon as I deselect the polygon (before I can even save edits) it adds the extra vertices back in!

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Has anyone seen anything like this?

  • in what coordinate system is your polygon ? Did you also change the central meridian of the data or only of the dataframe ? – radouxju Jun 22 '17 at 14:54
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    Does this link help? desktop.arcgis.com/en/arcmap/10.3/guide-books/map-projections/… – GBG Jun 22 '17 at 15:10
  • That link is very helpful, thanks. The data uses GCS_Mercury (a Plate_Carree projection) and I did only change the meridian of the dataframe. I'll see what can be done about reprojecting the data itself. – JMartin Jun 22 '17 at 15:43
  • Please use the edit button beneath your question to revise it with any requested clarifications. – PolyGeo Jul 5 '17 at 23:13