138 Austrian Journal of Statistics,Vol.34(2005),No.2,127-138 R.A.Maronna.Robust M-estimators of multivariate location and scatter.The Annals of S1 atistics,41):51-67,1976. R.A.Maronna and V.J.Yohai.The behavior of the Stahel-Donoho robust multivariate estimator.J.Am.Statist.Assoc.,90:330-341,1995. D.Pena and F.J Prieto.Multivariate outlier detection and robust covariance matrix esti- mation (with discussion).Technometrics,43(3):286-310,2001. D.M.Rocke and D.L.Woodruff.Identification of outliers in multivariate data.J.Am. S1 atist..Assoc.,91:1047-1061,1996 D.M.Rocke and D.L.Woodruff.A synthesis of outlier detection and cluster identi- fication.Technical report,University of California,Davis,Davis CA 95616,1999. http://handel.cipic.ucdavis.edu/dmrocke/Synth5.pdf. P.J.Rousseeuw and B.C.Van Zomeren.Unmasking multivariate outliers and leverage points.J.Am.Statist.Assoc.,85(411):633-651,1990. P.J.Rousseeuw.Multivariate estimation with high breakdown point.In W.Grossmann, G.Pflug,I.Vincze,and W.Wertz,editors,Mathematical Statistics and Applications, volume B,pages 283-297,Budapest,1985.Akademiai Kiad6. P.J.Rousseeuw and K.Van Driessen.A fast algorithm for the minimum covariance de- terminant estimator.Technometrics,41:212-223,1999. D.Swayne,D.Cook,and A.Buja.XGobi:Interactive dynamic data visualization in the X Windows system.Journal ofComputational and Graphical Statistics,7(1):113-130, 1998 D.E.Tyler.Some issues in the robust estimation of multivariate location and scatter.In W.Stahel and S.Weisberg,editors,Directions in Robust Statistics and Diagnostics 2, pages 327-336.Springer,New York,1991. Author's address: Prof.Peter Filzmoser Department of Statistics and Probability Theory Vienna University of Technology Wiedner HauptstraBe 8-10 A-1040 Vienna,Austria Tel.+4315880110733 Fax+4315880110799 E-mail:P.Filzmoser@tuwien.ac.at http://www.statistik.tuwien.ac.at/public/filz/138 Austrian Journal of Statistics, Vol. 34 (2005), No. 2, 127-138 R.A. Maronna. Robust M-estimators of multivariate location and scatter. The Annals of Statistics, 4(1):51–67, 1976. R.A. Maronna and V.J. Yohai. The behavior of the Stahel-Donoho robust multivariate estimator. J. Am. Statist. Assoc., 90:330–341, 1995. D. Pena and F.J Prieto. Multivariate outlier detection and robust covariance matrix esti- ˜ mation (with discussion). Technometrics, 43(3):286–310, 2001. D.M. Rocke and D.L. Woodruff. Identification of outliers in multivariate data. J. Am. Statist. Assoc., 91:1047–1061, 1996. D.M. Rocke and D.L. Woodruff. A synthesis of outlier detection and cluster identi- fication. Technical report, University of California, Davis, Davis CA 95616, 1999. http://handel.cipic.ucdavis.edu/ dmrocke/Synth5.pdf. P.J. Rousseeuw and B.C. Van Zomeren. Unmasking multivariate outliers and leverage points. J. Am. Statist. Assoc., 85(411):633–651, 1990. P.J. Rousseeuw. Multivariate estimation with high breakdown point. In W. Grossmann, G. Pflug, I. Vincze, and W. Wertz, editors, Mathematical Statistics and Applications, volume B, pages 283–297, Budapest, 1985. Akademiai Kiad ´ o. ´ P.J. Rousseeuw and K. Van Driessen. A fast algorithm for the minimum covariance de￾terminant estimator. Technometrics, 41:212–223, 1999. D. Swayne, D. Cook, and A. Buja. XGobi: Interactive dynamic data visualization in the X Windows system. Journal of Computational and Graphical Statistics, 7(1):113–130, 1998. D.E. Tyler. Some issues in the robust estimation of multivariate location and scatter. In W. Stahel and S. Weisberg, editors, Directions in Robust Statistics and Diagnostics 2, pages 327–336. Springer, New York, 1991. Author’s address: Prof. Peter Filzmoser Department of Statistics and Probability Theory Vienna University of Technology Wiedner Hauptstraße 8-10 A-1040 Vienna, Austria Tel. +43 1 58801 10733 Fax +43 1 58801 10799 E-mail: P.Filzmoser@tuwien.ac.at http://www.statistik.tuwien.ac.at/public/filz/