Abstract

In a recent paper, T. Kohonen and P. Somervuo have shown that self-organizing maps (SOMs) are not restricted to numerical data. They can also be defined for symbol strings, provided that one defines an average function for strings and that the adaptation process is performed off-line (batch). In this paper, we present two different methods for computing averages of strings, as well as an on-line version of the self-organizing map for strings. Both methods for computing averages are faster than the original one used by Kohonen and Somervuo, and one of them is suitable for on-line computation.

Citations