A methodology based on the concept of a variable string length GA (VGA) is
developed for determining automatically the number of hyperplanes for model
ing the class boundaries in a GA-classifier. The genetic operators and fitn
ess function are defined to take care of the variability in chromosome leng
th. It is proved that the method is able to arrive at the optimal number of
misclassifications after a sufficiently large number of iterations, and wi
ll need a minimal number of hyperplanes for this purpose. Experimental resu
lts on different artificial and real life data sets demonstrate that the cl
assifier. using the concept of a variable length chromosome, can automatica
lly determine an appropriate value of the number of hyperplanes, and also p
rovide performance better than that of the fixed length version. Its compar
ison with another approach using a VGA is provided. (C) 1998 Elsevier Scien
ce B.V. All rights reserved.