Self-Organizing Maps (SOM) Resources, a PatternRecognition related topic

• Samuel Kaski's doctoral thesis on Data Exploration Using Self-Organizing Maps, see especially Chapters 2 (Methods for exploratory data analysis) and 3 (Stages of SOM-based exploratory data analysis).
• SOM in the wild, or an example of how SOM are actually used in a real project: Unobtrusive User Modeling for Adaptive Hypermedia (preprint)
• Mat Buckland's SOM tutorial
• SOM Bibliography from Helsinki University of Technology
• multiple contributed SOM packages in R, as well as multiple packages that include SOM
  • package list:
    • kohonen - a fairly modern implementation, as well as fairly complete (although missing some crucial elements, like sammon maps.) Includes a nice adaptation to using SOMs for classification.
    • wccsom - builds upon kohonen, adding weighted cross-correlation. Very nice, indeed.
    • som - a bare bones SOM implementation, has quantization error, but no Umatrix, no component maps.
    • class - contains batchSOM implementation (from 1995!).
  • reflective question: how do you decide which package to use? Some suggested criteria:
    1. package quality
       • reflective question: how do you assess the quality of a package? Some suggested criteria:
         1. does it include unit tests?
         2. how comprehensive is the documentation?
         3. ... (what else)?
    2. what is the goal of your overall project? does your goal match the goal of the package?
    3. ... (what else)?

-- HilaryHolz - 03 Feb 2009