so this is a continuation of a previous post I had, but I think I have figured out a more streamlined approach. I think the questions is now different enough to warrant its own post. The challenge is the same and the number labeling of polygons corresponds to my other post here: How to loop through polygons in layer and apply calculations?

I have this polygons layer, and underneath that layer, I have a population count data layer (1 dot = 1 person). I then draw 1-mile buffers around the centroid of each polygon (These are conceptual examples of course as I have not actually figured out yet how to do this with my own data):

enter image description here

I count the number of points in each buffer, regardless of overlap, for each polygon centroid. The attribute table would look like this (though how can I ensure the counts will be attributed to their associated polygon centroid?):

Polgyon_centroid      GeoID     Count_within_buffer
               1         xx                      5
               2         xx                      6  
               3         xx                      4 
               4         xx                      5 
               5         xx                      5

Now, I isolated and deleted the regions where the buffers overlapped (left in white). Now, I want to count up the red dots within the pink area. However, I do not simply want to count this up as a single value for all pink area within the layer. This would forget that each of these buffers (or what remains of the original buffers) is attributed to the unique polygon centroid from which it was created. My attribute table has 5 rows, corresponding to the 5 polygon centroids I have. I now want to count up the red dots in the pink area of each buffer and enter it in the attribute table so these new count values correspond to the associated centroid:

enter image description here

So the new attribute table for the polygons layer would be:

Polgyon_centroid      GeoID     Count_within_buffer     Count_within_clipped_buffer
               1         xx                      5                                3  
               2         xx                      6                                3
               3         xx                      4                                4
               4         xx                      5                                3
               5         xx                      5                                2

How can I get this final attribute table for my polygons layer? The real challenge I see here is figuring out how make it so that the buffers actually correspond to the centroids they were created from, as opposed to just buffers that exist as a totally separate layer with no relation at all to the centroids they were created from.

1 Answer 1


Don't you think that my answer in your previous post will achieve your destiny? If no, please let me know why.

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