topic Select by location question in Geoprocessing Questions

Select by location question

NibiKhan — Wed, 18 Apr 2012 11:37:55 GMT

Hi there,

I have two layers grocery_stores (points) and neighbourhoods (polygons). I would like to select those neighbourhoods which have at least three grocery_stores. I am looking at the options in "select by location" in the selection drop down menu but nothing meets the requirement. Any suggestions on how to accomplish this?

Regards,
NK

Re: Select by location question

RyanForbes1 — Wed, 18 Apr 2012 13:24:40 GMT

NK,

There may be a pythonic way of achieving this if you're at all comfortable with it - but I think this might help you out: http://support.esri.com/en/knowledgebase/techarticles/detail/30779

I haven't done this myself but it looks as though it'll calculate the number of points within a polygon and then store it as an attribute in a layer - from there you could do a select by attribute where the value is >= 3

Re: Select by location question

TimothyHales — Wed, 18 Apr 2012 13:26:50 GMT

You can use Spatial Join to determine how many points are within each polygon. The output polygon feature class will have two new fields added (Join_Count and TARGET_FID). Join_Count indicates how many join features match each target feature (TARGET_FID). Then you can select by attribute those that have 3 or more.

About joining and relating tables

You can also right click the polygon layer in ArcMap > Joins and Relates > Join. Select the option to Join Data From Another Layer Based Upon Spatial Location. Then choose the points layer to join to. The output feature class will contain a count field for each polygon.