Laboratory of Computer and Information Science / Neural Networks Research Centre CIS Lab Helsinki University of Technology

About SOM Toolbox

Why? The "SOM Toolbox" project was initialized back in 1997 because there was no such thing as a proper SOM-library for MATLAB. MATLAB is a magnificient computing environment, but the tools in its neural networks toolbox for SOM were not really up to the state-of-the-art. On the other hand, the freeware SOM program package SOM_PAK is all well and good, but it's not nearly as flexible as the MATLAB environment. So the plan was to offer a simple, well documented MATLAB function package which is easy to use and modify in the diverse needs that different people unavoidably have.

Who? Numerous people have participated in the making of SOM Toolbox. In addition to the people listed in the copyright notice, Kimmo Kiviluoto, Jukka Parviainen, Mika Pollari have participated in it, not to mention those who have contributed code, given bug reports or other feedback. The common factor for us is to have been employed in the Laboratory of Information and Computer Science in the Helsinki University of Technology.


SOM Toolbox is Copyright (C) 2000-2005 by Esa Alhoniemi, Johan Himberg, Juha Parhankangas and Juha Vesanto.

The software library is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or any later version.

The software package is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

A number of functions in the package do not belong to the core SOM Toolbox, but have been contributed by various people. These functions may have a copyright notice of their own, but if not, this same copyright implicitly holds for them, too, except that the copyright is owned by the author of the function.

Licensing the library for proprietary programs

As stated in the GNU General Public License it is not possible to include this software library in a commercial proprietary program without written permission from the owners of the copyright. If you wish to obtain such permission, you can reach us by paper mail:

  SOM Toolbox team
  Laboratory of Computer and Information Science
  P.O.Box 5400
  FIN-02015 HUT 
and by email:

Versions and further development

The current version of the toolbox is 2.0beta. Further versions are not planned.


The members of the SOM Toolbox team have left CIS. Therefore, we cannot currently guarantee any support in using SOM Toolbox. If you have a question about SOM Toolbox that the documentation does not address, you can send e-mail to

System requirements

See documentation.

You are at: CIS → About SOM Toolbox

Page maintained by, last updated Friday, 18-Mar-2005 16:09:03 EET