Boosting and Bayesian Additive Trees for Two-Sample Comparison R package BATTS version 0.4.0 Implements boosting and Bayesian additive tree methods for two-sample comparison through density ratio estimation, following Awaya, Xu, and Ma (2025) <doi:10.48550/arXiv.2508.03059>. The package supports both point estimation and uncertainty quantification via Bayesian additive tree ensembles. Software Depends: R (>= 4.0.0) Imports: graphics, Rcpp, stats LinkingTo: Rcpp, RcppArmadillo Suggests: ggplot2, knitr, mvtnorm, rmarkdown, scales Naoki Awaya <nawaya@waseda.jp> Comprehensive R Archive Network (CRAN) Naoki Awaya [aut, cre, cph], Yuliang Xu [aut, cph], Li Ma [aut, cph] MIT + file LICENSE (https://CRAN.R-project.org/package=BATTS/LICENSE) 2026-11-13 application/tgz https://CRAN.R-project.org/package=BATTS doi:10.32614/CRAN.package.BATTS