stat340: Data and functions for BIAS at NMBU

#' SireHerd: Milk Production from Dairy Cows
#'
#' From a population of sires, three sires were chosen at random, and for each
#' of the sires the annual milk production for three of their daughters were
#' recorded. This data set also contains information of what herd the cows
#' belong to.
#'
#' @format A data frame with 24 observations (rows) and 3 variables (columns).
#' \tabular{llllr}{
#'   \tab \bold{Column name} \tab \bold{Data type} \tab \bold{Description} \tab \bold{Values}\cr
#'   \code{[,1]} \tab \code{milk} \tab integer \tab Milk produced from each cow in kg \tab (6063 - 7579)\cr
#'   \code{[,2]} \tab \code{herd} \tab factor \tab The cows live in 4 different groups \tab (1, 2, 3, 4)\cr
#'   \code{[,3]} \tab \code{sire} \tab factor \tab The father of the cow \tab (1, 2, 3)
#' }
#'
#' @details
#'
#' \itemize{
#'   \item Each sire has two daughters in each herd.
#'   \item The milk production is the response variable.
#'   \item The three sires are considered random effects since it is the whole
#'   population of sires we are interested in, not specifically this random
#'   sample of three sires.
#'   \item \code{sire} and \code{herd} are nested random effects.
#' }
#'
#' The sire data sets have been used in STAT210 and other courses at NMBU over
#' several years. While this data set consists of observed milk production for
#' 24 cows, the `sires` data has 40 observations. `sires` and `SireHerd` do not
#' contain the same observations.
#'
#' @seealso `sires`
#'
#' @examples
#'
#' # The structure of the object
#' str(SireHerd)
#'
#' # One box for daughters of the same sire in each herd,
#' # two cows per box
#' boxplot(milk ~ herd + sire, data = SireHerd)
#'
#' @docType data
#' @keywords datasets
#' @name SireHerd
#' @usage SireHerd
#'
"SireHerd"