warpbreaks {base}R Documentation

The Number of Breaks in Yarn during Weaving

Description

This data set gives the number of warp breaks per loom, where a loom corresponds to a fixed length of yarn.

Usage

data(warpbreaks)

Format

A data frame with 54 observations on 3 variables.
[,1] breaks numeric The number of breaks
[,2] wool factor The type of wool (A or B)
[,3] tension factor The level of tension (L, M, H)

Source

Tippet, L. H. C. (1950) Technological Applications of Statistics. Wiley. Page 106.

References

Tukey, J. W. (1977) Exploratory Data Analysis. Addison-Wesley.

McNeil, D. R. (1977) Interactive Data Analysis. Wiley.

Examples

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)

[Package Contents]