doByGroupwise Statistics, LSmeans, Linear Contrasts, UtilitiesFacilities for working with grouped data: 'do' something to data stratified 'by' some variables.LSmeans (least-squares means), general linear contrasts.Miscellaneous other utilitiesAuthor: Søren Højsgaard, Ulrich HalekohCRAN page:https://cran.r-project.org/web/packages/doBy/index.htmlFurther info at:http://people.math.aau.dk/~sorenh/software/doBy/https://github.com/hojsgaard/doBy