Random Start Forward Searches with Envelopes for Detecting Clusters in Multivariate Data

Abstract

During a forward search the plot of minimum Mahalanobis distances of observations not in the subset provides a test for outliers. However, if clusters are present in the data, their simple identification requires that there arc searches that initially include a preponderance of observations from each of the unknown clusters. We use random starts to provide such searches, combined with simulation envelopes for precise inference about clustering.