NEWS.md

In fitHeavyTail: Mean and Covariance Matrix Estimation under Heavy Tails

Changes in fitHeavyTail version 0.2.0 (2023-5-1)

• New methods OPP and POP for the estimation of nu: nu_OPP_estimator() and nu_POP_estimator().

• Function fit_mvt() updated using POP as default method for nu.

• Vignette updated.

• Functions fit_Tyler() and fit_Cauchy() now recover the missing scaling factor with the improved OPP-harmonic method.

• New contributors added for OPP and POP methods: Frederic Pascal and Esa Ollila.

Changes in fitHeavyTail version 0.1.4 (2022-5-11)

• No changes. Just that CRAN required to resubmit due to some issue with package ghyp.

Changes in fitHeavyTail version 0.1.3 (2022-4-14)

• New method for skewed t distributions: fit_mvst()

• New contributor added for fit_mvst(): Xiwen Wang.

• fit_mvt() and fit_mvst(): Now the bounds for nu estimation can be set as a global option, e.g.: options(nu_min = 4.2).

• Fixed description regarding covariance matrix for Cauchy distribution.

• fit_mvt(): It accepts weights as argument to weight differently the samples (as opposed to uniform weights).

• fit_mvt(): Many more methods to estimate nu iteratively (via argument nu_iterative_method).

• fit_mvt(): New argument scale_minMSE to include a correction factor in the covariance matrix for minimum MSE (still in development).

Changes in fitHeavyTail version 0.1.2 (2020-1-7)

• Vignette revised: detailed descriptions of the algorithms included.

• Comparison with additional existing benchmark sn::selm() included in the vignette.

• Now the three fitting functions also return the number of iterations and elapsed cpu_time.

• Significant revision of the fitting function fit_mvt(); in particular:

• the nu_target for the estimation of nu has been removed since it was not effective;

• several new options for the initial value of nu or fixed value of nu have been included; and

• improved and more robust estimation of nu at each EM iteration.

• Function fit_mvt() now allows the choice (via the argument na_rm) to drop the observations with NAs or impute them.

Changes in fitHeavyTail version 0.1.1 (2019-11-22)

• Initial release is on CRAN.

• It includes three functions for heavy tails fitting: fit_mvt(), fit_Tyler(), and fit_Cauchy().

• Vignette illustrates its use and comparison with existing packages.

• Tests are included.

• fit_mvt() can deal with NAs and a factor model structure on the covariance matrix.

Changes in fitHeavyTail version 0.1.0 (2017-11-04)

• Initial bare-bone implementation (not publicly released).

fitHeavyTail documentation built on May 1, 2023, 5:21 p.m.