Knowledge Base - Technical Articles
HowTo: Count the number of point features within a polygon
|Software:||ArcGIS - ArcEditor 8.3, 9.0, 9.1, 9.2, 9.3, 9.3.1, 10 ArcGIS - ArcInfo 9.0, 8.3, 9.1, 9.2, 9.3, 9.3.1, 10 ArcGIS - ArcView 8.3, 9.0, 9.1, 9.2, 9.3, 10, 9.3.1 ArcGIS for Desktop Advanced 10.2, 10.1, 10.2.1, 10.2.2 ArcGIS for Desktop Basic 10.2, 10.2.1, 10.2.2, 10.1 ArcGIS for Desktop Standard 10.2.1, 10.1, 10.2, 10.2.2|
Instructions provided describe how to count the number of point features that are contained in a polygon.
For help in determining how to symbolize your map based on the number of point features contained or intersecting a polygon, please refer to knowledge base article 43094, How to symbolize polygons based on the number of intersecting points.
Create a count field and a spatial join between the point shapefile and the polygon shapefile.
- In the attribute table of the point shapefile, create a field called 'Count' of type 'Short Integer'.
- Calculate the Count field equal to 1 by right-clicking the field name > Field Calculator > Enter a 1 in the white dialog area below "Count = ", and click OK.
- Right-click the polygon shapefile and click Joins and Relates > Joins. Click the dropdown list and select 'Join data from another layer based on spatial location'.
- Specify the point shapefile from Step 1.
- Select the first bullet (Each polygon is given a summary of the numeric attributes...) and check the 'Sum' box.
- Specify an output location, and click OK.
- A polygon shapefile with the 'Count' field indicating how many point features lie within each polygon feature is now present. This is usually named 'Sum_Count' or 'Count_'.
Last Modified: 9/22/2015
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