mkcls: Training of word classes.

mkcls is a tool to train word classes by using a maximum-likelihood-criterion. The resulting word classes are especially suited for language models or statistical translation models. The program mkcls was written by Franz Josef Och.

Usage of mkcls:

mkcls [-nnum] [-ptrain] [-Vfile] opt

-V output classes

-n number of optimization runs (Default: 1); larger number => better results

-p filename of training corpus (Default: ‘train’)


mkcls -c80 -n10 -pkorpus -Vkats opt

(generates 80 classes for the corpus ‘in’ and writes the classes in ‘out’)

In order to compile mkcls you may need:

  • a recent version of the GNU compiler (2.95 or higher)

It is released under the GNU Public License (GPL).




Source code:

newest version on NEW


  • compiles now also with gcc versions 2.95 – 3.3 / MacOS X

mkcls.2001-01-12.tar.gz (old version)