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HDMaxShrink provides test-guided interpolation between full-model and submodel coefficient estimates. The current workflow separates submodel selection, estimation, and held-out evaluation.

Install

Use R 4.1 or later, C++17 and the declared Rcpp/RcppArmadillo dependencies.

remotes::install_github("byuzbasi/HDMaxShrink", upgrade = "never")

This is a GitHub research package. The associated methods record is the 2026 arXiv preprint, not a journal publication.

Follow the current example

The repository’s self-contained quick-start script generates independent selection, analysis and test samples. It uses CPSS-LASSO for optional additions to a prespecified mandatory core, a joint Ridge full model, and an exact-null SVD submodel. Run it deliberately after installation:

source(system.file("examples", "quickstart.R", package = "HDMaxShrink"))

The script uses 1,000 predictors, 20 complementary selection pairs and 199 conditional Gaussian draws. It is one synthetic illustration, not the paper’s production study. This guide displays the command without executing that calibration during the website build.

Saved quick-start illustration: selection frequencies, held-out errors and coefficients.
Saved quick-start illustration: selection frequencies, held-out errors and coefficients.

This figure is retained from the repository’s fixed-seed quick-start example; it is not new benchmark evidence. Reproduce it with the linked script and report the exact package version used.

Choose a documented route

Route Entry point Scope
Current independent-selection route cpss_select_core(), fit_cpss_ridge_shrinkage() CPSS-selected exact-null submodel and all-predictor Ridge endpoint
Prespecified-core alternative fit_hd_shrinkage() Retained joint square-root-LASSO workflow
Historical sensitivity routes fit_partial_sqrt_lasso_shrinkage(), fit_ridge_mcp_shrinkage() Explicitly retained research modes, not silent replacements
Inspect estimates coef(), predict() Original-scale coefficients and predictions

The retained technical guide covers several frameworks; its square-root-LASSO section is an alternative to the current CPSS/Ridge route. Consult the function reference for the selected route rather than mixing their arguments or inferential assumptions.

Read diagnostics before interpreting shrinkage

Selection and analysis samples must be independent for the conditional argument. A selected submodel is not necessarily a true null. Inspect rank, test calibration and convergence information, and keep held-out data out of selection. Classical James–Stein dominance is not asserted. The optional CPSS-MCP sensitivity requires the declared grpreg dependency.

See data and reproduction for input roles, source provenance, version reporting and validation boundaries.