| warpbreaks {datasets} | 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
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, New York, NY. Page 106.
References
McNeil D. (1977). Interactive Data Analysis: A Practical Primer. John Wiley & Sons. ISBN 978-0471026310.
Tukey J. W. (1977). Exploratory Data Analysis, number 2 series Addison-Wesley series in behavioral science. Addison-Wesley Publishing Company. ISBN 9780201076165.
See Also
xtabs for ways to display these data as a table.
Examples
require(stats); require(graphics)
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 datasets version 4.6.0 Index]