risdr 0.3.1

CRAN release candidate

• Added executable examples for the principal simulation, covariance, sufficient dimension reduction, prediction, slicing, structural dimension, and subspace-assessment workflows.
• Hardened dependency, metadata, URL, spelling, and citation records for the first CRAN submission.
• Declared both knitr and rmarkdown as vignette builders so that vignettes rebuild correctly when suggested packages are not pre-installed.
• Added a package spelling dictionary and R-hub validation workflow.
• Corrected structural-dimension examples to request an admissible maximum dimension directly, avoiding expected dimension-reduction warnings.
• Excluded the repository-level CITATION.cff file from source-package builds while retaining inst/CITATION for the installed R package.
• Retained the Zenodo DOI as the permanent identifier for the archived version 0.3.0 release and made the installed-package citation report the installed package version.
• Completed local, GitHub Actions, pkgdown, coverage, URL, spelling, and selected R-hub checks successfully.

risdr 0.3.0

Package interface

• Promoted repeated predictive cross-validation and complexity-aware cross-validation to the exported API.
• Added explicit cov_args, stabilization_args, and sdr_args controls to prevent component arguments from leaking into unrelated functions.
• Improved prediction for one-row inputs, reordered named columns, and alternative structural dimensions.
• Restricted the real-data workflow to its verified continuous-response scope.

Numerical and validation changes

• Added ridge and Ledoit-Wolf covariance methods to central method validation.
• Replaced the observation-wise Ledoit-Wolf accumulation loop with an algebraically equivalent vectorised calculation.
• Vectorised the principal Hessian directions kernel calculation.
• Strengthened integer, missing-value, covariance, slice, survival-indicator, and resampling validation.
• Corrected rho = 0 handling for AR(1) simulation and guarded sparse-basis generation when the predictor dimension is small.
• Added a user-supplied true-basis option and ensured that simulated training and test samples share the same central subspace.
• Made projection matrices robust to non-orthonormal full-rank bases.
• Return NA with a warning when MAPE is undefined because an observed value is zero.

Documentation and release engineering

• Added five vignettes, a structured pkgdown configuration, a professional README, contribution guidance, issue templates, and release documentation.
• Expanded the testthat suite across validation, covariance estimation, SDR kernels, prediction, dimension selection, resampling, simulation, plotting, and real-data helpers.
• Added multi-platform R CMD check, test coverage, and pkgdown workflows.
• Added selected supplied thesis outputs under inst/extdata as provenance fixtures. Legacy simulation prediction outputs are explicitly marked for targeted rerun because the original script regenerated the true basis in the test sample.
• Added the supplied aligned EPI training and test matrices, with dimensions, column alignment, and SHA-256 provenance recorded in inst/extdata/README.md.
• Added a configurable corrected reproduction script for Simulations A, B1, and B2. Corrected files use distinct names and do not overwrite legacy outputs.

Compatibility

• The principal user-facing function names from the supplied baseline are retained.
• Version metadata now records the agreed development release number, 0.3.0.