2

I have the huge number of points spread across some map.

Is it possible to calculate the mean value of a parameter in the points of a small area and make one point for the same so that the total number of points in the map can be reduced?

2

One tool available in QGIS processing toolbox is SAGA Points thinning tool (in Processing toolbox | SAGA | Vector point tools).

When activated, you will find two input parameters to set:

  • Attribute: The attribute field you want to calculate mean.
  • Resolution: The diameter (m) of a search circle in which a representative point is chosen or newly created. Increase this value if you need to severely reduce the points.

It returns a Thinned Points layer, and its attribute table has the mean (among other parameters = count, mean, min, max, sd) of the value you chose for Attribute parameter.

2

I think that there isn't exist an unique tool to do it. I propose you the following process from an example like this: enter image description here

  1. CONVEX HULL around you points using a grouping attribute.
  2. POLYGON CENTROIDS to get the central point of those new polygons. This could work as you aggregation point. It should seems something like this: enter image description here
  3. Calculate statistics by categories from your point data. enter image description here
  4. You will get the following statistics. enter image description here
  5. Last step is to make a join of the centroid with those grouped statistics. enter image description here

Hope it helps.

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.