topic Re: Clustering points based on geographic location (an island) in Spatial Statistics Questions

Clustering points based on geographic location (an island)

AndreaDort — Thu, 15 Nov 2012 14:04:02 GMT

Hello,
Dataset of 6500 points distributed over a geographic area (an island).
I need to find where these points significantly cluster and also view outliers. Cluster/outlier analysis doesn't seem to help since it requires an input field and because I want to evaluate based on location, the point file has no relevant fields.
Essentially I need to identify clusters of points within a specific search area (the island).
Any ideas??
Big thanks
Andrea

Re: Clustering points based on geographic location (an island)

ObiOfoegbu — Tue, 19 Feb 2013 15:14:27 GMT

Hello,
Dataset of 6500 points distributed over a geographic area (an island).
I need to find where these points significantly cluster and also view outliers. Cluster/outlier analysis doesn't seem to help since it requires an input field and because I want to evaluate based on location, the point file has no relevant fields.
Essentially I need to identify clusters of points within a specific search area (the island).
Any ideas??
Big thanks
Andrea

Have you tried the buffer tool to atleast visually give you the clustered points and show outliers. You can either use linear or field to specify what points would be close to each other and visually have a polygon feature around the clustered points. Outliers would be polygons with fewest points in them. Hope this helps

Re: Clustering points based on geographic location (an island)

KristinAldous — Wed, 20 Feb 2013 16:15:37 GMT

Hi Andrea,

It sounds like you might be able to use hot spot analysis with some data prep. The help topic gives and explanation of using the 'fishnet tool' or a spatial join to get a count of points within a grid or local area.

http://resources.arcgis.com/en/help/main/10.1/index.html#//005p00000011000000