A METHOD OF IDENTIFYING INFLUENTIAL DATA IN FUZZY CLUSTERING

In multivariate statistical methods, it is important to identify influ ential observations for a reasonable interpretation of the data struct ure, In this paper, we propose a method for identifying influential da ta in the fuzzy C-means (FCM) algorithm, To investigate such data, we consider a perturbation of the data points and evaluate the effect of a perturbation. As a perturbation, we consider two cases: one is the c ase in which the direction of a perturbation is specified and the othe r is the case in which the direction of a perturbation is not specifie d, By computing the change in the clustering result of FCM when given data points are slightly perturbed, we can look for data points that g reatly affect the result, Also, we confirm an efficacy of the proposed method by numerical examples.