For the OP's benefit, you can also find these called Self Organizing Map (thus the acronym SOM).
If you have access to MatLab, there's a nice SOM package available for free, including some examples. I don't have the reference at the moment but can find it if anyone is interested.
> From: "DarkYoung" <firstname.lastname@example.org> > Organization: http://groups.google.com > Newsgroups: sci.crypt.random-numbers,sci.stat.math,comp.ai.neural-nets > Date: 17 Feb 2005 04:15:32 -0800 > Subject: Re: Forecasting numbers based on number frequencies. > > I've found that when you suspect there might be a pattern to something, > but don't know what factors it's based on, a Kohonen Self-Organising > Network is just the thing. They attune themselves to statistical > regularities in the input. > > Now I'm not certain about complete downloadable programs for K-SOMs, > but there is a decent Java framework for building them at > www.jooneworld.com, and I've been told WinSOM at > http://www.foretrade.com/WinSOM.htm may be what you need. > > I hope that's useful. > Bonnie >