I am currently using QGIS 2.18.15 and I have two sets of polygon layer data. I would like to use the Select by Location research tool in order to isolate the polygons that have their centers within the other separate layer. ArcMap has a specific "have their centroid in" option when selecting by location. I don't see that QGIS has this. Is there an equivalent?

  • I don't know how the ArcMap tool handle this but the centroid of a polygon is not always inside the polygon (depending of the shape of the polygon). You should look at this point on any solution you come by to prevent unwanted result.
    – J.R
    Apr 17 '19 at 14:26

There is no direct equivalent in Qgis core, but you can use the "Select Within" plugin, which should do exactly what you need (it adds an entry in the vector menu):

Select Within plugin interface

Otherwise, you would need to extract the centroid as a new layer, then make the selection on it.

  • I've installed the plugin. Now where do I go to access it and use it?
    – Niki
    Mar 17 '18 at 20:25
  • It adds an entry in the vector menu.
    – Leyan
    Mar 17 '18 at 20:29
  • Thanks. Found it. But, it didn't work. No features were selected. Any ideas?
    – Niki
    Mar 17 '18 at 20:32
  • By default, it uses "using selected features", which you need to disable to use the whole layer.
    – Leyan
    Mar 17 '18 at 20:37

For Select Within to work both layers have to be in the same CRS. They cannot simply be overlapping in the project window.


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