fitHeavyTail-package {fitHeavyTail}

fitHeavyTail: Mean and Covariance Matrix Estimation under Heavy Tails

Description

Robust estimation methods for the mean vector, scatter matrix, and covariance matrix (if it exists) from data (possibly containing NAs) under multivariate heavy-tailed distributions such as angular Gaussian (via Tyler's method), Cauchy, and Student's t distributions. Additionally, a factor model structure can be specified for the covariance matrix. The latest revision also includes the multivariate skewed t distribution. The package is based on the papers: Sun, Babu, and Palomar (2014); Sun, Babu, and Palomar (2015); Liu and Rubin (1995); Zhou, Liu, Kumar, and Palomar (2019); Pascal, Ollila, and Palomar (2021).

Functions

fit_Tyler, fit_Cauchy, fit_mvt, and fit_mvst.

Help

For a quick help see the README file: GitHub-README.

For more details see the vignette: CRAN-vignette.

Author(s)

Daniel P. Palomar and Rui Zhou

References

Ying Sun, Prabhu Babu, and Daniel P. Palomar, "Regularized Tyler's Scatter Estimator: Existence, Uniqueness, and Algorithms," IEEE Trans. on Signal Processing, vol. 62, no. 19, pp. 5143-5156, Oct. 2014. <https://doi.org/10.1109/TSP.2014.2348944>

Ying Sun, Prabhu Babu, and Daniel P. Palomar, "Regularized Robust Estimation of Mean and Covariance Matrix Under Heavy-Tailed Distributions," IEEE Trans. on Signal Processing, vol. 63, no. 12, pp. 3096-3109, June 2015. <https://doi.org/10.1109/TSP.2015.2417513>

Chuanhai Liu and Donald B. Rubin, "ML estimation of the t-distribution using EM and its extensions, ECM and ECME," Statistica Sinica (5), pp. 19-39, 1995.

Chuanhai Liu, Donald B. Rubin, and Ying Nian Wu, "Parameter Expansion to Accelerate EM: The PX-EM Algorithm," Biometrika, Vol. 85, No. 4, pp. 755-770, Dec., 1998

Rui Zhou, Junyan Liu, Sandeep Kumar, and Daniel P. Palomar, "Robust factor analysis parameter estimation," Lecture Notes in Computer Science (LNCS), 2019. <https://arxiv.org/abs/1909.12530>

Esa Ollila, Daniel P. Palomar, and Frédéric Pascal, "Shrinking the Eigenvalues of M-estimators of Covariance Matrix," IEEE Trans. on Signal Processing, vol. 69, pp. 256-269, Jan. 2021. <https://doi.org/10.1109/TSP.2020.3043952>

Frédéric Pascal, Esa Ollila, and Daniel P. Palomar, "Improved estimation of the degree of freedom parameter of multivariate t-distribution," in Proc. European Signal Processing Conference (EUSIPCO), Dublin, Ireland, Aug. 23-27, 2021. <https://doi.org/10.23919/EUSIPCO54536.2021.9616162>