I am searching for the kernel function the ArcGIS tool "Kernel Density" is using. The ArcGIS help mentions the following: "The kernel function is based on the quadratic kernel function described in Silverman (1986, p. 76, equation 4.5)." I have access to the 1998 print of this book where I can find the equation on the very same page. However, when implementing the kernel, I get rather different results from the Gaussian variant, for example. Can therefore anybody tell me the correct kernel function ArcGIS is using? I think it has to be modified to integrate to 1 or something like that.
I remember this question to be answered in the old ESRI forums and I think that I even have the link to it:
http://forums.esri.com/Thread.asp?c=93&f=995&t=98735
Sadly, the link does not work anymore. (Is there a way to access the old forums?)
Thank you very much in advance.
Bill Huber reported on this in an alternate place and on his website
and this link contains references to the book and Bill's comments as well
and his discussion here, which most likely drew from the original link
sharing to Spatial Analyst given the slow spatial stats market