[Illinois] KohonenSOM

By Bara Saadah1, Nahil Sobh1, Jessica S Johnson1, NanoBio Node1

1. University of Illinois at Urbana-Champaign

This tool implements the Kohonen self-organizing map (SOM) algorithm

Launch Tool

You must login before you can run this tool.

Version 1.4b - published on 06 Aug 2014

doi:10.4231/D3251FK96 cite this

This tool is closed source.

View All Supporting Documents




Published on


In this tool, KohonenSOM is used to train neural networks using simple (competitive) unsupervised learning, in which only the winner is trained, and progress to full SOM(self-organizing maps) strategies in which feature maps of various types are formed. Unsupervised learning causes output units to specialize for specific input patterns. The tool determines the input patterns and the number of input units required to represent those patterns, by finding the numbers of rows and columns of the input array. The number of output units must be specified in the tool under nOut. The neighborhood is the area that stores the topological properties of the input space. It must be set to 0 when we wish to have the output unit with the largest response to a given pattern trained by itself on each iteration during competitive learning. The KohonenSOM algorithm is plausible neurobiologically and approximates the synaptic integration as the computation ny a neural unit of its weighted sum. The normalization equation in the tool keeps the total amount of synaptic input to a neural unit constant. This appears to the same role in real neurons.

Sponsored by

NanoBio Node, University of Illinois Champaign-Urbana


Anastasio, Thomas J. Tutorial on Neural Systems Modeling. Sunderland: Sinauer Associates, 2010. Print.

Cite this work

Researchers should cite this work as follows:

  • Bara Saadah, Nahil Sobh, Jessica S Johnson, NanoBio Node (2014), "[Illinois] KohonenSOM," http://nanohub.org/resources/kohonensom. (DOI: 10.4231/D3251FK96).

    BibTex | EndNote