R/data-fertiliza.r

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

#' Fertilization experiment data.  
#' @description
#' Data contains volume data at plot-level for a fertilization
#' experiment.  
#' @usage
#' data(fertiliza)
#' @format Contains two variables, as follows:
#' \describe{
#'   \item{treat}{Treatment level.}
#'   \item{volume}{Plot-level volume, in m\eqn{^{3}}{^3}.}
#'  }
#' @source 
#' The data were provided by Dr Christian Salas-Eljatib (Universidad de Chile,
#'  Santiago, Chile).  
#' @references
#' not yet 
#' @examples
#' data(fertiliza)
#' head(fertiliza)
#' class(fertiliza$treat)
#' unique(fertiliza$treat)
#' means.g <- tapply(fertiliza$volume,fertiliza$treat,mean);means.g
#' sds.g <- tapply(fertiliza$volume,fertiliza$treat,sd);sds.g
#' ns.g <- tapply(fertiliza$volume,fertiliza$treat,length);ns.g
'fertiliza'