Repeated Measures with Attrition: Sample Sizes and Power Levels for 2 Groups R package rmass2 version 0.0.0.2 For the calculation of sample size or power in a two-group repeated measures design, accounting for attrition and accommodating a variety of correlation structures for the repeated measures; details of the method can be found in the scientific paper: Donald Hedeker, Robert D. Gibbons, Christine Waternaux (1999) <doi:10.3102/10769986024001070>. Software Depends: stats (>= 3.6.2) Suggests: knitr, rmarkdown, testthat (>= 3.0.0), utils (>= 4.3.1) Soumya Sahu <ssahu6@uic.edu> Comprehensive R Archive Network (CRAN) Yiheng Wei [aut] (ORCID: <https://orcid.org/0009-0007-2211-8850>), Soumya Sahu [aut, cre], Donald Hedeker [aut] GPL-2 GPL-3 2023-09-20 application/tgz https://CRAN.R-project.org/package=rmass2 doi:10.32614/CRAN.package.rmass2