I am studying a monkey species, I have GPS observation points which I used to make a convex polygon (Hull). I also have all of the survey trails imported and displayed in QGIS (See screen shot for clearer understanding). As I have over 2700hr of survey tracks I want to select only the tracks or parts of the tracks that are within this polygon. The end goal is to get a more accurate estimate for survey effort within the core range (convex polygon). (using QGIS 2.18.2)enter image description here

I have tried vector->research tools-> select by location which only found tracks that were wholly within the convex hull shapefile.

I then tried vector->geoprocessing tools -> clip which wasn't able to run giving the following error:

2017-05-16T15:45:56 2   Uncaught error while executing algorithm
            Traceback (most recent call last):
              File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/core/GeoAlgorithm.py", line 203, in execute
              File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/algs/qgis/Clip.py", line 71, in processAlgorithm
              File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/core/outputs.py", line 326, in getVectorWriter
                crs, options)
              File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/tools/vector.py", line 610, in __init__
                uri = GEOM_TYPE_MAP[geometryType] + "?uuid=" + unicode(uuid.uuid4())
            KeyError: 1005


Once converting my track file from multiparts to single parts (Vector->geometry tools-> multiparts to single parts). This was difficult as a newbie as most people refer to it as MULTILINESTRINGZ and LINESTRING on stackexchange. I was then able to clip the track shapefile to the convex hull polygon.

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    What GIS software are you using? – BERA Apr 30 '17 at 18:31
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    Welcome to GIS SE. As a new user please take the Tour. You haven't specified what GIS software you are using, but every GIS package is capable of this operation, so you need to specify what you have tried, and what problem you encountered. – Vince Apr 30 '17 at 18:33
  • Sorry, I am using QGIS 2.18.2 I would need a basic run through since it is my first time completing this task. – Nebulloyd Apr 30 '17 at 22:20
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    Please edit the question in response to requests for clarification, as described in the Tour. It's not fair to those who would answer to need to mine the comments for critical information. – Vince May 1 '17 at 11:07
  • Welcome to gis.stackexchange! Please note that a good question on this site is expected to show some degree of research on your part, i.e. what you have tried and - if applicable - code so far. For more info, you can check our faq. – underdark May 1 '17 at 17:10

Select by location (Vector->Research Tools->Select by location) is not going to be exactly what you want. So the simplest solution here is to clip the paths by the convex hull. This gives you a new output tracks file of just the tracks in the polygon

| improve this answer | |
  • thanks for the suggestion. Unfortunately this is only selecting the tracks entirely within the polygon shapefile. I have since tried vector->geoprocessing->clip but I get an error '1005 see log...' which I will post in the question above. – Nebulloyd May 16 '17 at 14:46
  • Please read my reply carefully - I said that select by location is NOT what you want for the very reason you state. Which is why you need to clip or intersect your data. As for the issue with clipping (which is what you DO need to do) - see this post for a solution – MappaGnosis May 16 '17 at 15:00

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