kpf2

3 Questions about using point data (not raster data) to calculate Getis-Ord Gi*...?

Discussion created by kpf2 on Jul 19, 2011
Latest reply on May 12, 2015 by RGerasim
Hi,

I am trying to find the hotspots of combining two types of data, crimes and crashes.

My first question is how to use point data to calculate Getis-Ord Gi*.

My point data is positive skewed and spread out, so I can not a good fix distance band which makes the corner points have 8 neighbors but the middle points do not includes all features. Please see the image for its kernel density map.

For this kind of data, is it better that I aggregate it as grid data for hot spot analysis or any other methods? 

The second question is about the different results by using kernel density and Gi*.

Is kernel density used to focus on the area with high crash/crime risk, and Gi* is used to identify the data cluster pattern? So, if there is an area with extremely high value, but its neighbors are all low value, will Gi* identify it as a hot spot?

The third question is about using unbiased kernel density in Network.

Does ArcGIS 10 or other software programs provide this function?

Thank you very much. :)



pei-fen

Attachments

Outcomes