Statistics and Computing

, Volume 10, Issue 4, pp 339–348

Robust mixture modelling using the t distribution

  • D. Peel
  • G. J. McLachlan


Normal mixture models are being increasingly used to model the distributions of a wide variety of random phenomena and to cluster sets of continuous multivariate data. However, for a set of data containing a group or groups of observations with longer than normal tails or atypical observations, the use of normal components may unduly affect the fit of the mixture model. In this paper, we consider a more robust approach by modelling the data by a mixture of t distributions. The use of the ECM algorithm to fit this t mixture model is described and examples of its use are given in the context of clustering multivariate data in the presence of atypical observations in the form of background noise.

finite mixture models normal components multivariate t components maximum likelihood EM algorithm cluster analysis 


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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • D. Peel
    • 1
  • G. J. McLachlan
    • 2
  1. 1.Department of MathematicsUniversity of QueenslandQueenslandAustralia
  2. 2.Department of MathematicsUniversity of QueenslandQueenslandAustralia

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