Package: MEMWAS Type: Package Title: Mixed-Effects Models with Autocorrelation Structures Version: 0.9.4.9002 Date: 2026-08-20 Authors@R: c( person("Enoch", "Kang", role = c("aut", "cre", "trl"), email = "y.enoch.kang@gmail.com", comment = c(ORCID = "0000-0002-4903-942X")) ) Description: Fits longitudinal mixed-effects models through a registered 'C++' numerical backend. Supported serial covariance structures include first-order autoregressive (AR(1)), exponential or Ornstein-Uhlenbeck, higher-order autoregressive (AR(p)), first-order autoregressive moving-average (ARMA(1,1)), compound symmetry, Toeplitz, and unstructured covariance. Serial processes can be unified or attached independently to numeric predictor loadings. Candidate temporal structures can be ranked on a common sample by dependence-component grouped cross-validation, the Akaike information criterion, the Bayesian information criterion, or log-likelihood. Clustered, crossed, and nested random intercepts and slopes are assembled jointly with diagonal or term-specific unstructured covariance. Available approximation methods include Laplace, saddlepoint likelihood with latent Laplace integration, adaptive Gaussian quadrature, full-covariance Gaussian variational inference, and penalized quasi-likelihood. Penalized smooth mean terms include ordinary and cyclic P-splines, factor-by and varying-coefficient terms, tensor products, shrinkage smooths, and whole-term selection. Term-specific penalties, grouped fold-local smoothing selection, null-space constraints, and smooth effective degrees of freedom remain separate from elastic-net coefficient shrinkage while the smooth mean and serial covariance are fitted jointly. Bootstrap resampling preserves the declared dependence components. The mixed-effects framework is inspired by Laird and Ware (1982) ; generalized-model approximations are inspired by Breslow and Clayton (1993) ; and serial covariance formulations are inspired by Pinheiro and Bates (2000) . The run-time fitting interface imports no third-party 'R' packages. License: GPL (>= 3) Depends: R (>= 4.1.0) Imports: stats, utils Suggests: knitr, rmarkdown, testthat (>= 3.0.0) NeedsCompilation: yes Config/roxygen2/version: 8.0.0 VignetteBuilder: knitr, rmarkdown Config/testthat/edition: 3 Language: en-US Encoding: UTF-8 Repository: https://enochkang.r-universe.dev Date/Publication: 2026-08-22 14:50:51 UTC RemoteUrl: https://github.com/enochkang/memwas RemoteRef: HEAD RemoteSha: b1d8658c7e524b9d30b42592785af7bc646e4bf2 Packaged: 2026-10-21 09:19:48 UTC; root Author: Enoch Kang [aut, cre, trl] (ORCID: ) Maintainer: Enoch Kang