| % File src/library/datasets/man/ToothGrowth.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{ToothGrowth} |
| \docType{data} |
| \alias{ToothGrowth} |
| \title{The Effect of Vitamin C on Tooth Growth in Guinea Pigs} |
| \description{ |
| The response is the length of odontoblasts (cells responsible for |
| tooth growth) in 60 guinea pigs. Each animal received one of three |
| dose levels of vitamin C (0.5, 1, and 2 mg/day) by one of two delivery |
| methods, orange juice or ascorbic acid (a form of vitamin C and coded |
| as \code{VC}). |
| } |
| \usage{ToothGrowth} |
| \format{ |
| A data frame with 60 observations on 3 variables. |
| \tabular{rlll}{ |
| [,1] \tab len \tab numeric \tab Tooth length\cr |
| [,2] \tab supp \tab factor \tab Supplement type (VC or OJ).\cr |
| [,3] \tab dose \tab numeric \tab Dose in milligrams/day |
| } |
| } |
| \source{ |
| C. I. Bliss (1952). |
| \emph{The Statistics of Bioassay}. |
| Academic Press. |
| } |
| \references{ |
| McNeil, D. R. (1977). |
| \emph{Interactive Data Analysis}. |
| New York: Wiley. |
| |
| Crampton, E. W. (1947). |
| The growth of the odontoblast of the incisor teeth as a criterion of |
| vitamin C intake of the guinea pig. |
| \emph{The Journal of Nutrition}, \bold{33}(5), 491--504. |
| \doi{10.1093/jn/33.5.491}. |
| } |
| \examples{ |
| require(graphics) |
| coplot(len ~ dose | supp, data = ToothGrowth, panel = panel.smooth, |
| xlab = "ToothGrowth data: length vs dose, given type of supplement") |
| } |
| \keyword{datasets} |