Dunn’s cluster validity index as a contrast measure of VAT images

This paper addresses the relationship between the visual assessment of cluster tendency (VAT) algorithm and Dunnpsilas cluster validity index. We present an analytical comparison in conjunction with numerical examples to demonstrate that the effectiveness of VAT in showing cluster tendency is directly related to Dunnpsilas index. This analysis is important to understanding the underlying theory of VAT and VAT-based algorithms and, more generally, other algorithms that are based on, or similar to, Primpsilas Algorithm.