I have several point .shp files that were geocoded using OpenStreetMap. I located a base map to overlay the point files. I would like to create an artificial boundary based on an 80/20 rule for each point file. For example, the boundary would be drawn around 80% of the points and this process would follow for the rest of the point .shp files that have been geocoded. I searched through previous post and found Converting point sets to polygon boundaries?. This response represents what I would like to achieve. Therefore I attempted the procedures and fail short of the goal of obtaining arbitrary boundaries that would overlay. I have attached an image for a visual?

I am after any insight on how to create artificial boundaries based off an 80/20 rule.

I am new user to QGIS.

enter image description here

  • When you say that you tried what was referenced in the other post, what failed? Did you receive an error message? – MaryBeth May 20 '16 at 17:07
  • In the other post I followed item number 12, I was able to create the Voronoi plogyons but it distorted the base map. Therefore, I followed the comments to clip but the boundary lines from the Voronoi plogyons disappeared. – M. Dot May 20 '16 at 17:22

I would create a Concave Hull (QGIS plugin) for the outer polygon. Calculate the distance from each point to the Outer polygon. Sort the Points by distance, deleting the smallest 20%. Generate a new Concave Hull around the remaining 80%.

| improve this answer | |
  • Thank you for your response. I am using the 2.8 and received an error stating "invalid or have unfulfilled dependencies" and "The plugin is broken/ Python said: cannot import". – M. Dot May 20 '16 at 17:27
  • The Convex Hull tool is part of Core QGIS, Vector, Geoprocessing Tools. Perhaps try it instead. – klewis May 20 '16 at 18:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.