Groupwise Statistics, LSmeans, Linear Estimates, Utilities
Søren Højsgaard <sorenh@math.aau.dk> and Ulrich Halekoh
    <uhalekoh@health.sdu.dk>
Utility package containing:
    1) Facilities for working with grouped data: 'do' something to data
    stratified 'by' some variables.
    2) LSmeans (least-squares means), general linear estimates.
    3) Restrict functions to a smaller domain.
    4) Miscellaneous other utilities.
boot, broom, cowplot, Deriv, dplyr, ggplot2, MASS, Matrix,
modelr, microbenchmark, rlang, tibble, tidyr,
geepack, knitr, lme4, markdown, multcomp, pbkrtest (>=
0.4-8.1), survival, testthat (>= 2.1.0)