R/Lettuce.R

In VSNC/vsnc: Data and code in Agri

#' Effects of nitrogen, phosphorus and potasium on lettuce seedlings
#' 
#' The Lettuce dataset contains data from an experiment growing lettuce seedings. There are three treatment factors: nitrogen (N), phosphorus (P) and potash (K). It was arranged in three replicates, each containing three blocks, and a different set of contrasts of the N:P:K interaction was confounded with blocks within each replicate.
#' @format 
#' \describe{A data frame with 32 observations on the following six variables:
#' 
#' \item{Replicate}{a factor specifying the replicates.}
#' \item{Block}{a factor specifying the blocks.}
#' \item{N}{a factor specifying the amount of nitrogen fertiliser.}
#' \item{P}{a factor specifying the amount of phosphorus fertiliser.}
#' \item{K}{a factor specifying the amount of potasium fertiliser.}
#' \item{Yield}{a numerical vector recording the yields.}
#' }
#' @source 
#' Cochran, W.G. & Cox, G.M. (1957). Experimental Designs (2nd edition), page 196.
"Lettuce"