RXshrink (version 1.4.3)

unr.aug: Augment calculations performed by unr.ridge() to prepare for display of eliptical confidence regions for pairs of biased coefficient estimates using plot.unr.biv()

Description

This function makes classical (rather than Bayesian) Normal distribution-theory calculations of the form proposed in Obenchain(1977). Instead of providing "new" confidence regions for estimable linear functions, Generalized Ridge Regression (GRR) can focus interest on estimates that are within traditional confidence intervals and regions but which deviate reasonably from the centroid of that interval or region.

Usage

unr.aug(urobj)

Arguments

urobj

An output object of class "unr.ridge".

Value

An output list object of class "unr.aug"...

p

Number of regression predictor variables.

LMobj

The lm() output object for the model fitted using unr.ridge().

bstar

The p by p+2 matrix of shrunken GRR coefficients. The first p correspond to "knots" on piecewise linear splines, and the last column contains minimum MSE risk estimates.

mcal

p+2 increasing measures of shrinkage "Extent". The first is 0 for the OLS (BLUE) estimate, the next to last denotes the "Extent" most likely to yield minimum MSE risk, and the last is p [this shrinkage terminus is frequently outside of the unr.biv() plot frame].

vnams

Names of variables used in the GRR model.

References

Obenchain RL. (1977) Classical F-Tests and Confidence Regions for Ridge Regression. Technometrics 19, 429-439. http://doi.org/10.1080/00401706.1977.10489582

Obenchain RL. (2020) Ridge TRACE Diagnostics. https://arxiv.org/abs/2005.14291

Obenchain RL. (2020) RXshrink_in_R.PDF RXshrink package vignette-like file. http://localcontrolstatistics.org

See Also

unr.ridge, mofk and kofm