Welch-Satterthwaite Approximation for t-Distribution Differences R package wstdiff version 1.0.0 Implements the Welch-Satterthwaite approximation for differences of non-standardized t-distributed random variables in both univariate and multivariate settings. The package provides methods for computing effective degrees of freedom and scale parameters, as well as distribution functions for the approximated difference distribution. The methodology extends the classical Welch-Satterthwaite framework from variance combinations to t-distribution differences through careful moment matching. Methods build on the classical Welch-Satterthwaite approach described in Welch (1947) <doi:10.1093/biomet/34.1-2.28> and Satterthwaite (1946) <doi:10.2307/3002019>. Software Depends: R (>= 3.5.0) Imports: stats Suggests: testthat (>= 3.0.0), mvtnorm, knitr, rmarkdown Yusuke Yamaguchi <yamagubed@gmail.com> Comprehensive R Archive Network (CRAN) Yusuke Yamaguchi [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=wstdiff/LICENSE) 2025-11-11 application/tgz https://CRAN.R-project.org/package=wstdiff doi:10.32614/CRAN.package.wstdiff