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I want to make a polygon selection based on a specific number of points.
For example, I want to select those polygons that contain more than 30 points. I don't want to select every polygon that contains a point.

I tried to do something with ArcGis's data reviewer and I checked spatial join but I didn't find anything.

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    Could you clarify? You say you want to select polygons which contain more than 30 points from some other layer and then you say you do not want to select polygons? – user30184 Jun 25 '14 at 14:25
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    Are you looking for a Python solution? – Aaron Jun 25 '14 at 15:06
  • yes why not. Do you have something in mind? – Harris P. Jun 25 '14 at 16:06
  • There isn't a 1 step solution, combine gis.stackexchange.com/questions/58485/… with Branco's answer below. – matt wilkie Jun 25 '14 at 16:11
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Ok, here is a way to do it that isn't too complicated.

Create a new short integer field in your points layer.

Assign each feature a value of 1.

Spatial join your polygon layer to your points layer.

For your options, choose that each polygon will be given a summary of the numeric attributes.... option and summarize the values by Sum.

In your new layer, look for those who have the summed value of 30 or more.

Then you can export those selected features into a new layer. To select features from your original layer, do a select by location query against this exported layer, and you should have it.

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    right idea, but can be even simpler: Spatial Join creates a field automatically called Join_Count, which is the number of times the Join Features (the points) intersect the Target Features (the polygons). (NB: other relationships besides /intersect/ can be used.). Also, you don't need to export, just use a Definition Query on the Spatial Join result to select only Join_Count > 30; see Displaying a subset of features in a layer – matt wilkie Jun 25 '14 at 16:09
  • Branco nice idea. Thx. But I think Matt is correct! I 'll try it. Furthermore I'll try to create a tool with model builder In order to select and export the polygons with a suitable expression. I don't know if I can upload files thought – Harris P. Jun 25 '14 at 18:42

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