| % File src/library/datasets/man/chickwts.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2014 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{chickwts} |
| \docType{data} |
| \alias{chickwts} |
| \title{Chicken Weights by Feed Type} |
| \description{ |
| An experiment was conducted to measure and compare the effectiveness |
| of various feed supplements on the growth rate of chickens. |
| } |
| \usage{chickwts} |
| \format{ |
| A data frame with 71 observations on the following 2 variables. |
| \describe{ |
| \item{\code{weight}}{a numeric variable giving the chick weight.} |
| \item{\code{feed}}{a factor giving the feed type.} |
| } |
| } |
| \source{ |
| Anonymous (1948) |
| \emph{Biometrika}, \bold{35}, 214. |
| } |
| \details{ |
| Newly hatched chicks were randomly allocated into six groups, and each |
| group was given a different feed supplement. Their weights in grams |
| after six weeks are given along with feed types. |
| } |
| \references{ |
| McNeil, D. R. (1977) |
| \emph{Interactive Data Analysis}. |
| New York: Wiley. |
| } |
| \examples{ |
| require(stats); require(graphics) |
| boxplot(weight ~ feed, data = chickwts, col = "lightgray", |
| varwidth = TRUE, notch = TRUE, main = "chickwt data", |
| ylab = "Weight at six weeks (gm)") |
| anova(fm1 <- lm(weight ~ feed, data = chickwts)) |
| opar <- par(mfrow = c(2, 2), oma = c(0, 0, 1.1, 0), |
| mar = c(4.1, 4.1, 2.1, 1.1)) |
| plot(fm1) |
| par(opar) |
| } |
| \keyword{datasets} |