| 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) |
There are measurements on 9 looms for each of the six types of warp (AL, AM, AH, BL, BM, BH).
Source
Tippett, 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.
See Also
xtabs for ways to display these data as a table.
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)