Kohonen's SOM with cache

The Kohonen Self Organizing Map (SOM), is a topology preserving map that maps data from higher dimensions onto a (typically) two dimensional grid of lattice points[3]. The aim of Self-Organization is to generate a topology preserving mapping, where the neighborhood relations in the input space are preserved as well as possible, in the neighborhood relations of the units of the map[2]. One of the most time consuming steps during the training of the SOM is the sub-problem of locating the winner node for a given sample. A winner node is the best matching unit for each input vector.