\Header{warpbreaks}{The Number of Breaks in Yarn during Weaving}
\keyword{datasets}{warpbreaks}
\begin{Description}\relax
This data set gives the number of warp breaks per loom, where a loom
corresponds to a fixed length of yarn.\end{Description}
\begin{Usage}
\begin{verbatim}data(warpbreaks)\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame with 54 observations on 3 variables.
\Tabular{rlll}{
\code{[,1]} & \code{breaks}  & numeric & The number of breaks\\
\code{[,2]} & \code{wool}    & factor  & The type of wool (A or B)\\
\code{[,3]} & \code{tension} & factor  & The level of tension (L, M, H)
}\end{Format}
\begin{Source}\relax
Tippet,  L. H. C. (1950)
\emph{Technological Applications of Statistics.}
Wiley.  Page 106.\end{Source}
\begin{References}\relax
Tukey, J. W. (1977) \emph{Exploratory Data Analysis.}
Addison-Wesley.

McNeil, D. R. (1977) \emph{Interactive Data Analysis.}  Wiley.\end{References}
\begin{Examples}
\begin{ExampleCode}
data(warpbreaks)
summary(warpbreaks)
opar <- par(mfrow = c(1,2), oma = c(0, 0, 1.1, 0))
plot(breaks ~ tension, data = warpbreaks, col = "lightgray",
     varwidth = TRUE, subset = wool == "A", main = "Wool A")
plot(breaks ~ tension, data = warpbreaks, col = "lightgray",
     varwidth = TRUE, subset = wool == "B", main = "Wool B")
mtext("warpbreaks data", side = 3, outer = TRUE)
par(opar)
summary(fm1 <- lm(breaks ~ wool*tension, data = warpbreaks))
anova(fm1)
\end{ExampleCode}
\end{Examples}

