Nonparametric genetic clustering: Comparison of validity indices

Variable string length genetic algorithm (GA) is used for developing a novel nonparametric clustering technique when the number of clusters is not fixed a priori. Chromosomes in the same population may now have different lengths since they encode different number of clusters. The crossover operator is redefined to tackle the concept of variable string Length. Cluster validity index is used as a measure of the fitness of a chromosome. The performance of several cluster validity indices, namely, Davies-Bouldin (DB) index, Dunn's index, two of its generalized versions and a recently developed index, in appropriately partitioning a data set, are compared.