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I have a set of polygon centerlines created using voronoi polygons. The method seems to work well for what I want to accomplish, but these 'tail' remnants are throwing off successive analysis (attached an image). Is there a way to remove them from the lines automatically? Note: I would prefer if this could be done with QGIS tools, but can create a python script if necessary.

I would be open to switching methods for obtaining polygon centerlines. I know there is a 'Polygon Centerline' tool in ArcMap, but I don't have access to it.

"Tails" on line features

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  • Are these "tails", topologically speaking, a single line segment or do they go out and back again? Because if your diagram above is a single feature and the tails are single segments of a multi-line feature then converting multi-parts to features then removing small features should do the job. Got sample data?
    – Spacedman
    Nov 22, 2016 at 14:26
  • For clarification, are they like ____/\____ ("out and back") or ____|____ (true topological branches)
    – Spacedman
    Nov 22, 2016 at 14:28
  • Hi Spacedman, the 'tails' were true topological branches (I). I determined that they were a result of jagged source polygons, creating messy voronoi polygons (that made spatial queries impossible). All solved now, but thanks for your assistance!
    – GIS_Canuck
    Nov 22, 2016 at 16:27
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    @GIS_Canuck - Just an FYI, you should add the '@' symbol before someone's name so that they can receive a notification in their inbox. Otherwise they won't receive your message ;)
    – Joseph
    Nov 22, 2016 at 16:29
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    Cheers @Joseph, appreciate it!
    – GIS_Canuck
    Nov 22, 2016 at 16:32

2 Answers 2

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I ended up simplifying the source polygons that were used to create the voronoi polygons, making it a much cleaner surface to work with. This eliminated the dangles, as there were no lines remaining that couldn't be selected through a spatial query. Thanks to all who replied!

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    Don't forget to accept your answer by clicking the green-faded tick on the left-hand side, this let's everyone know your problem has been solved :)
    – Joseph
    Jul 12, 2017 at 8:59
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Have you seen this question:

Automated removal of dangles / loose ends in line with QGIS?

In ArcGIS you could use Delete Dangles tool.

Removes lines that are shorter than the specified length and do not connect to other features on both ends.

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    Thanks artwork21. I hadn't seen that question, but it doesn't necessarily help. I ended up simplifying the source polygons that were used to create the voronoi polygons, making it a much cleaner surface to work with. No more loose ends!
    – GIS_Canuck
    Nov 21, 2016 at 21:20
  • @GIS_Canuck - You should post your comment as an answer =)
    – Joseph
    Nov 22, 2016 at 11:03

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