Hi,

Kernel estimation could be done many ways. If you are generalising or 
generating statistics for square celled raster data or points then I may be 
able to help.

It may be that convolve operations (or something else) in JAI, that others on 
this list can help you with, are better suited to what you want, than some of 
the things I go on about below.

There are some univariate and bivariate statistics for point distributions that 
can be got using a Geographically Weighted Statistics (GWS) package I started 
developing some time ago:
http://www.geog.leeds.ac.uk/people/a.turner/src/andyt/java/gws/

GWS is based on Grids which evolved from GeoTools long ago, but has not been 
merged back. This is a library for 2D square celled raster data. More on Grids 
at the following:
http://www.geog.leeds.ac.uk/people/a.turner/src/andyt/java/grids/

There is code for two different types of kernel in Grids, but it should be 
reasonably easy to detail any weighting scheme or function to apply. One kernel 
is a standard normal kernel - based on the mean and variance of the cell 
centroid distances (within a specified region). I can detail the other if 
wanted... Grids was designed for processing entire grids on a cell by cell 
basis generating outputs usually for the same spatial frame. 

I have not developed GWS for some time, but I would like to revisit this. I 
have been doing some work on Grids processing Digital Elevation Models of late 
and should probably make a new code release if you plan to use it. Maybe I can 
work with you to get something you want. Anyway, good luck!

Best wishes,

Andy

-----Original Message-----
From: [EMAIL PROTECTED] on behalf of Jody Garnett
Sent: Sat 26/01/2008 02:19
To: Mairon Belchior
Cc: [email protected]
Subject: Re: [Geotools-gt2-users] Kernel Estimation
 
A couple uDig based projects have hooked up to the R stats package that 
supports that sort of thing. I am not quite sure how they did it ... 
check out the Diva GIS project for more information (that was one of the 
teams I remember doing the work).

Jody

> Hi All,
>
> I work as a research assistant and I need to create a Kernel Map. Does 
> anyone know if there is a function in Geotools API that I can do 
> Kernel Density Estimation or if somebody knows any java API that does it.
>
> I´d appreciate any help.
>
> Mairon Belchior
>
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