Abstract
The family of multiple scaled mixtures of multivariate normal (MSMN) distributions has been shown to be a powerful tool for modeling data that allow different marginal amounts of tail weight. An extension of the MSMN distribution is proposed through the incorporation of a vector of shape parameters, resulting in the skew multiple scaled mixtures of multivariate normal (SMSMN) distributions. The family of SMSMN distributions can express a variety of shapes by controlling different degrees of tailedness and versatile skewness in each dimension. Some characterizations and probabilistic properties of the SMSMN distributions are studied and an extension to finite mixtures thereof is also discussed. Based on a sort of selection mechanism, a feasible ECME algorithm is designed to compute the maximum likelihood estimates of model parameters. Numerical experiments on simulated data and three real data examples demonstrate the efficacy and usefulness of the proposed methodology.
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Data Availability
Data and R codes for the implementation of our methodology are available at https://github.com/a-mahdavi/EM.mixSMSMN.git
References
Abanto-Valle, C. A., Bandyopadhyay, D., Lachos, V. H., & Enriquez, I. (2010). Robust Bayesian analysis of heavy-tailed stochastic volatility models using scale mixtures of normal distributions. Computational Statistics & Data Analysis, 54(12), 2883–2898.
Andrews, D. F., & Mallows, C. L. (1974). Scale mixtures of normal distributions. Journal of the Royal Statistical Society: Series B (Methodological), 36(1), 99–102.
Andrews, J. L., & McNicholas, P. D. (2012). Model-based clustering, classification, and discriminant analysis via mixtures of multivariate \(t\)-distributions: The \(t\) EIGEN family. Statistics and Computing, 22, 1021–1029.
Arellano-Valle, R. B., & Azzalini, A. (2006). On the unification of families of skew-normal distributions. Scandinavian Journal of Statistics, 33(3), 561–574.
Arellano-Valle, R. B., Branco, M. D., & Genton, M. G. (2006). A unified view on skewed distributions arising from selections. Canadian Journal of Statistics, 34(4), 581–601.
Bagnato, L., Punzo, A., Bagnato, L., & Punzo, A. (2021). Unconstrained representation of orthogonal matrices with application to common principal components. Computational Statistics, 36(2), 1177–1195.
Banfield, J. D., & Raftery, A. E. (1993). Model-based Gaussian and non-Gaussian clustering. Biometrics, 803–821.
Barndorff-Nielsen, O. E. (1997). Normal inverse Gaussian distributions and stochastic volatility modelling. Scandinavian Journal of Statistics, 24(1), 1–13.
Baudry, J. P., Raftery, A. E., Celeux, G., Lo, K., & Gottardo, R. (2010). Combining mixture components for clustering. Journal of Computational and Graphical Statistics, 19(2), 332–353.
Bevilacqua, M., Caamaño-Carrillo, C., Arellano-Valle, R. B., & Morales-Oñate, V. (2021). Non-Gaussian geostatistical modeling using (skew) \(t\) processes. Scandinavian Journal of Statistics, 48(1), 212–245.
Branco, M. D., & Dey, D. K. (2001). A general class of multivariate skew-elliptical distributions. Journal of Multivariate Analysis, 79(1), 99–113.
Browne, R. P., & McNicholas, P. D. (2014). Orthogonal Stiefel manifold optimization for eigen-decomposed covariance parameter estimation in mixture models. Statistics and Computing, 24, 203–210.
Browne, R. P., & McNicholas, P. D. (2014). Estimating common principal components in high dimensions. Advances in Data Analysis and Classification, 8, 217–226.
Browne, R. P., McNicholas, P. D., & Sparling, M. D. (2011). Model-based learning using a mixture of mixtures of Gaussian and uniform distributions. IEEE Transactions on Pattern Analysis and Machine Intelligence, 34(4), 814–817.
Cabral, C. R. B., Lachos, V. H., & Prates, M. O. (2012). Multivariate mixture modeling using skew-normal independent distributions. Computational Statistics & Data Analysis, 56(1), 126–142.
Celeux, G., & Govaert, G. (1995). Gaussian parsimonious clustering models. Pattern Recognition, 28(5), 781–793.
Charytanowicz, M., Niewczas, J., Kulczycki, P., Kowalski, P. A., Łukasik, S., & Żak, S. (2010). Complete gradient clustering algorithm for features analysis of x-ray images. In Information Technologies in Biomedicine: vol 2 (pp. 15–24). Springer Berlin Heidelberg.
Choy, S. T. B., & Smith, A. (1997). Hierarchical models with scale mixtures of normal distributions. Test, 6, 205–221.
Cuesta-Albertos, J. A., Gordaliza, A., & Matrán, C. (1997). Trimmed \(k\)-means: An attempt to robustify quantizers. The Annals of Statistics, 25(2), 553–576.
Dang, U. J., Punzo, A., McNicholas, P. D., Ingrassia, S., & Browne, R. P. (2017). Multivariate response and parsimony for Gaussian cluster-weighted models. Journal of Classification, 34, 4–34.
Dempster, A. P., Laird, N. M., & Rubin, D. B. (1977). Maximum likelihood from incomplete data via the EM algorithm. Journal of the Royal Statistical Society: Series B (Methodological), 39(1), 1–22.
Ferreira, C. S., Bolfarine, H., & Lachos, V. H. (2020). Linear mixed models based on skew scale mixtures of normal distributions. Communications in Statistics-Simulation and Computation, 51(12), 7194–7214.
Ferreira, C. S., Lachos, V. H., & Bolfarine, H. (2016). Likelihood-based inference for multivariate skew scale mixtures of normal distributions. AStA Advances in Statistical Analysis, 100, 421–441.
Flury, B. N., & Gautschi, W. (1986). An algorithm for simultaneous orthogonal transformation of several positive definite symmetric matrices to nearly diagonal form. SIAM Journal on Scientific and Statistical Computing, 7(1), 169–184.
Forbes, F., & Wraith, D. (2014). A new family of multivariate heavy-tailed distributions with variable marginal amounts of tailweight: Application to robust clustering. Statistics and Computing, 24(6), 971–984.
Franczak, B. C., Tortora, C., Browne, R. P., & McNicholas, P. D. (2015). Unsupervised learning via mixtures of skewed distributions with hypercube contours. Pattern Recognition Letters, 58, 69–76.
Gallaugher, M. P., Tomarchio, S. D., McNicholas, P. D., & Punzo, A. (2022). Multivariate cluster weighted models using skewed distributions. Advances in Data Analysis and Classification, 1–32.
Garay, A. M., Lachos, V. H., Bolfarine, H., & Cabral, C. R. (2017). Linear censored regression models with scale mixtures of normal distributions. Statistical Papers, 58, 247–278.
Hennig, C. (2015). What are the true clusters? Pattern Recognition Letters, 64, 53–62.
Hubert, L., & Arabie, P. (1985). Comparing partitions. Journal of Classification, 2, 193–218.
Kaufman, L., & Rousseeuw, P. J. (2008). Finding groups in data: An introduction to cluster analysis. John Wiley & Sons.
Lee Lee, S. X., & McLachlan, G. J. (2013). Model-based clustering and classification with non-normal mixture distributions. Statistical Methods & Applications, 22(4), 427–454.
Lee, S. X., & McLachlan, G. J. (2019). Scale mixture distribution (pp. 1–16). Wiley StatsRef: Statistics Reference Online.
Lichman, M. (2013). UCI machine learning repository Irvine, CA: University of California, School of Information and Computer Science. http://archive.ics.uci.edu/ml
Lin, T. I. (2009). Maximum likelihood estimation for multivariate skew normal mixture models. Journal of Multivariate Analysis, 100(2), 257–265.
Lin, T. I. (2010). Robust mixture modeling using multivariate skew \(t\) distributions. Statistics and Computing, 20, 343–356.
Lin, T. I. (2014). Learning from incomplete data via parameterized \(t\) mixture models through eigenvalue decomposition. Computational Statistics & Data Analysis, 71, 183–195.
Lin, T. I., Lee, J. C., & Hsieh, W. J. (2007a). Robust mixture modeling using the skew \(t\) distribution. Statistics and Computing, 17, 81–92.
Lin, T. I., Lee, J. C., & Yen, S. Y. (2007b). Finite mixture modelling using the skew normal distribution. Statistica Sinica, 909–927.
Lin, T. I., & Wang, W. L. (2022). Multivariate linear mixed models with censored and nonignorable missing outcomes, with application to AIDS studies. Biometrical Journal, 64(7), 1325–1339.
Lin, T. I., Wu, P. H., McLachlan, G. J., & Lee, S. X. (2015). A robust factor analysis model using the restricted skew-\(t\) distribution. Test, 24(3), 510–531.
Liu, C., & Rubin, D. B. (1994). The ECME algorithm: A simple extension of EM and ECM with faster monotone convergence. Biometrika, 81(4), 633–648.
Liu, M., & Lin, T. I. (2015). Skew-normal factor analysis models with incomplete data. Journal of Applied Statistics, 42(4), 789–805.
Mahdavi, A., Amirzadeh, V., Jamalizadeh, A., & Lin, T. I. (2021). Maximum likelihood estimation for scale-shape mixtures of flexible generalized skew normal distributions via selection representation. Computational Statistics, 36, 2201–2230.
Maier, L. M., Anderson, D. E., De Jager, P. L., Wicker, L. S., & Hafler, D. A. (2007). Allelic variant in CTLA4 alters T cell phosphorylation patterns. Proceedings of the National Academy of Sciences, 104(47), 18607–18612.
Mazza, A., & Punzo, A. (2020). Mixtures of multivariate contaminated normal regression models. Statistical Papers, 61(2), 787–822.
Meng, X. L., & Rubin, D. B. (1993). Maximum likelihood estimation via the ECM algorithm: A general framework. Biometrika, 80(2), 267–278.
Pelleg, D. (2000). Extending \(K\)-means with efficient estimation of the number of clusters in ICML. In Proceedings of the 17th international conference on machine learning (pp. 277–281).
Prates, M. O., Lachos, V. H., & Cabral, C. R. B. (2013). mixsmsn: Fitting finite mixture of scale mixture of skew-normal distributions. Journal of Statistical Software, 54, 1–20.
Punzo, A., & Bagnato, L. (2020). Allometric analysis using the multivariate shifted exponential normal distribution. Biometrical Journal, 62(6), 1525–1543.
Punzo, A., & Bagnato, L. (2021). The multivariate tail-inflated normal distribution and its application in finance. Journal of Statistical Computation and Simulation, 91(1), 1–36.
Punzo, A., & Bagnato, L. (2022). Dimension-wise scaled normal mixtures with application to finance and biometry. Journal of Multivariate Analysis, 191, 105020.
Punzo, A., & Bagnato, L. (2022). Multiple scaled symmetric distributions in allometric studies. The International Journal of Biostatistics, 18(1), 219–242.
Punzo, A., & McNicholas, P. D. (2016). Parsimonious mixtures of multivariate contaminated normal distributions. Biometrical Journal, 58(6), 1506–1537.
Punzo, A., & McNicholas, P. D. (2017). Robust clustering in regression analysis via the contaminated Gaussian cluster-weighted model. Journal of Classification, 34, 249–293.
Punzo, A., & Tortora, C. (2021). Multiple scaled contaminated normal distribution and its application in clustering. Statistical Modelling, 21(4), 332–358.
R Core Team. (2019). R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria
Schumacher, F. L., Lachos, V. H., & Matos, L. A. (2021). Scale mixture of skew-normal linear mixed models with within-subject serial dependence. Statistics in Medicine, 40(7), 1790–1810.
Schwarz, G. (1978). Estimating the dimension of a model. The Annals of Statistics, 461–464.
Tomarchio, S. D., Bagnato, L., & Punzo, A. (2022). Model-based clustering via new parsimonious mixtures of heavy-tailed distributions. AStA Advances in Statistical Analysis, 1–33.
Tortora, C., ElSherbiny, A., Browne, R. P., Franczak, B. C., McNicholas, P. D., & Amos, D. D. (2020). MixGHD: Model-based clustering, classification and discriminant analysis using the mixture of generalized hyperbolic distributions. R package version 2.3.4.
Tortora, C., Franczak, B. C., Browne, R. P., & McNicholas, P. D. (2019). A mixture of coalesced generalized hyperbolic distributions. Journal of Classification, 36, 26–57.
Wang, W. L., Jamalizadeh, A., & Lin, T. I. (2020). Finite mixtures of multivariate scale-shape mixtures of skew-normal distributions. Statistical Papers, 61, 2643–2670.
Wang, W. L., & Lin, T. I. (2022). Robust clustering via mixtures of \(t\) factor analyzers with incomplete data. Advances in Data Analysis and Classification, 16(3), 659–690.
Wang, W. L., Liu, M., & Lin, T. I. (2017). Robust skew-\(t\) factor analysis models for handling missing data. Statistical Methods & Applications, 26, 649–672.
Wraith, D., & Forbes, F. (2015). Location and scale mixtures of Gaussians with flexible tail behaviour: Properties, inference and application to multivariate clustering. Computational Statistics & Data Analysis, 90, 61–73.
Young, D. S., & Hunter, D. R. (2010). Mixtures of regressions with predictor-dependent mixing proportions. Computational Statistics & Data Analysis, 54(10), 2253–2266.
Zareifard, H., & Khaledi, M. J. (2013). Non-Gaussian modeling of spatial data using scale mixing of a unified skew Gaussian process. Journal of Multivariate Analysis, 114, 16–28.
Zeller, C. B., Cabral, C. R., & Lachos, V. H. (2016). Robust mixture regression modeling based on scale mixtures of skew-normal distributions. Test, 25, 375–396.
Zeller, C. B., Cabral, C. R. B., Lachos, V. H., & Benites, L. (2019). Finite mixture of regression models for censored data based on scale mixtures of normal distributions. Advances in Data Analysis and Classification, 13, 89–116.
Acknowledgements
The authors are grateful to the Editor-in-Chief, the Guest Editor, and three anonymous referees for their valuable comments and constructive suggestions which greatly improved the content of this paper.
Funding
T.I. LIN is grateful for the financial support from the National Science and Technology Council of Taiwan under Grant no. NSTC 112-2118-M-005-004-MY3. A.F. Desmond acknowledges the support of NSERC Canada under Discovery Grant no. 401273.
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Mahdavi, A., Desmond, A.F., Jamalizadeh, A. et al. Skew Multiple Scaled Mixtures of Normal Distributions with Flexible Tail Behavior and Their Application to Clustering. J Classif (2024). https://doi.org/10.1007/s00357-024-09470-6
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DOI: https://doi.org/10.1007/s00357-024-09470-6