R/data-chicksw.r

In datana: Datasets and Functions to Accompany Analisis De Datos Con R

#' Chicken growth data.  
#' @description
#' The body weights of the chicks were measured at birth and every second day 
#' thereafter until day 20. They were 
#' also measured on day 21. There were four groups on chicks on different
#'  protein diets.  
#' @usage
#' data(chicksw)
#' @format Contains four variables, as follows:
#' \describe{
#' \item{chick}{An ordered factor with levels different giving a unique 
#' identifier for the chick. The ordering of the
#'             levels groups chicks on the same diet together and orders 
#'             them according to their final weight 
#'             (lightest to heaviest) within diet.}
#' \item{diet}{A factor with levels 1,2,3 and 4 indicating which experimental 
#' diet the chick received.}
#'   \item{time}{A numeric vector giving the number of days since birth when 
#'   the measurement was made.}
#'   \item{weight}{A numeric vector giving the body weight of the chick (gm).}
#'  }
#' @source 
#' The data were obtained from the \eqn{alr4} library.  
#' @references
#' Crowder M, Hand D. 1990. Analysis of Repeated Measures. Chapman and Hall
#' @examples
#' data(chicksw)    
#' head(chicksw) 
'chicksw'