<?xml version="1.0" encoding="utf-8" ?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:r="https://r-universe.dev"><channel><title>ziwei-chenchen.r-universe.dev</title><link>https://ziwei-chenchen.r-universe.dev</link><description>Recent package updates in ziwei-chenchen</description><generator>R-universe</generator><image><url>https://github.com/ziwei-chenchen.png</url><title>R packages by ziwei-chenchen</title><link>https://ziwei-chenchen.r-universe.dev</link></image><lastBuildDate>Sun, 10 May 2026 12:27:31 GMT</lastBuildDate><item><title>[ziwei-chenchen] savvyGLM 0.1.4</title><author>ziwei.chen.3@citystgeorges.ac.uk (Ziwei Chen)</author><description>Provides a flexible framework for fitting generalized
linear models (GLMs) with slab and shrinkage estimators.
Methods include the Stein estimator (St), Diagonal Shrinkage
(DSh), Simple Slab Regression (SR), Generalized Slab Regression
(GSR), Ledoit-Wolf Linear Shrinkage (LW), Quadratic-Inverse
Shrinkage (QIS), and Shrinkage (Sh), all integrated into the
iteratively reweighted least squares (IRLS) algorithm. This
approach enhances estimation accuracy, convergence, and
robustness in the presence of multicollinearity. The
best-fitting model is selected based on the Akaike Information
Criterion (AIC). Methods are related to methods described in
Marschner (2011) &lt;doi:10.32614/RJ-2011-012&gt;, Asimit et al.
(2025) &lt;https://openaccess.city.ac.uk/id/eprint/35005/&gt;, Ledoit
and Wolf (2004) &lt;doi:10.1016/S0047-259X(03)00096-4&gt;, and Ledoit
and Wolf (2022) &lt;doi:10.3150/20-BEJ1315&gt;.</description><link>https://github.com/r-universe/ziwei-chenchen/actions/runs/25629602664</link><pubDate>Sun, 10 May 2026 12:27:31 GMT</pubDate><r:package>savvyGLM</r:package><r:version>0.1.4</r:version><r:status>success</r:status><r:repository>https://ziwei-chenchen.r-universe.dev</r:repository><r:upstream>https://github.com/ziwei-chenchen/savvyglm</r:upstream><r:article><r:source>savvyGLM.Rmd</r:source><r:filename>savvyGLM.html</r:filename><r:title>savvyGLM: Shrinkage Methods for Generalized Linear Models</r:title><r:created>2025-04-03 21:22:13</r:created><r:modified>2026-05-10 12:27:31</r:modified></r:article></item><item><title>[ziwei-chenchen] savvyPR 0.1.0</title><author>ziwei.chen.3@citystgeorges.ac.uk (Ziwei Chen)</author><description>Implements the Savvy Parity Regression 'savvyPR'
methodology for multivariate linear regression analysis. The
package solves an optimization problem that balances the
contribution of each predictor variable to ensure estimation
stability in the presence of multicollinearity. It supports two
distinct parameterization methods, a Budget-based approach that
allocates a fixed loss contribution to each predictor, and a
Target-based approach (t-tuning) that utilizes a relative
elasticity weight for the response variable. The package
provides comprehensive tools for model estimation, risk
distribution analysis, and parameter tuning via
cross-validation (PR1, PR2, and PR3 model types) to optimize
predictive accuracy. Methods are based on Asimit, Chen, Ichim
and Millossovich (2026)
&lt;https://openaccess.city.ac.uk/id/eprint/35005/&gt;.</description><link>https://github.com/r-universe/ziwei-chenchen/actions/runs/26328716511</link><pubDate>Wed, 18 Mar 2026 17:11:33 GMT</pubDate><r:package>savvyPR</r:package><r:version>0.1.0</r:version><r:status>success</r:status><r:repository>https://ziwei-chenchen.r-universe.dev</r:repository><r:upstream>https://github.com/ziwei-chenchen/savvypr</r:upstream><r:article><r:source>savvyPR_example.Rmd</r:source><r:filename>savvyPR_example.html</r:filename><r:title>Savvy Parity Regression Model Estimation with 'savvyPR'</r:title><r:created>2026-03-05 10:53:10</r:created><r:modified>2026-03-18 17:08:30</r:modified></r:article></item><item><title>[ziwei-chenchen] savvySh 0.1.1</title><author>ziwei.chen.3@citystgeorges.ac.uk (Ziwei Chen)</author><description>Implements a suite of shrinkage estimators for
multivariate linear regression to improve estimation stability
and predictive accuracy. Provides methods including the Stein
estimator, Diagonal Shrinkage, the general Shrinkage estimator
(solving a Sylvester equation), and Slab Regression (Simple and
Generalized). These methods address Stein's paradox by
introducing structured bias to reduce variance without
requiring cross-validation, except for 'ShrinkageRR' where the
intensity is chosen by minimizing an explicit Mean Squared
Error (MSE) criterion. Methods are based on Asimit, V., Cidota,
M. A., Chen, Z., and Asimit, J. (2025)
&lt;https://openaccess.city.ac.uk/id/eprint/35005/&gt;.</description><link>https://github.com/r-universe/ziwei-chenchen/actions/runs/25986323333</link><pubDate>Wed, 18 Mar 2026 16:50:39 GMT</pubDate><r:package>savvySh</r:package><r:version>0.1.1</r:version><r:status>success</r:status><r:repository>https://ziwei-chenchen.r-universe.dev</r:repository><r:upstream>https://github.com/ziwei-chenchen/savvysh</r:upstream><r:article><r:source>savvySh.Rmd</r:source><r:filename>savvySh.html</r:filename><r:title>savvySh: Shrinkage Methods for Linear Regression Estimation</r:title><r:created>2025-03-24 17:27:08</r:created><r:modified>2026-03-18 16:43:51</r:modified></r:article></item></channel></rss>