The data frame TIREWEAR
contains measurements for the amount of tread loss in thousandths of an inch after 10,000 miles of driving.
TIREWEAR
A data frame with 16 observations on the following 3 variables:
wear
(tread loss measured in thousandths of an inch)
treat
(a factor with levels A
, B
, C
, and D
)
block
(a factor with levels Car1
, Car2
, Car3
, and Car4
)
Ugarte, M. D., Militino, A. F., and Arnholt, A. T. 2015. Probability and Statistics with R, Second Edition. Chapman & Hall / CRC.
par(mfrow=c(1, 2), cex = 0.8)
with(data = TIREWEAR,
interaction.plot(treat, block, wear, type = "b", legend = FALSE))
with(data = TIREWEAR,
interaction.plot(block, treat, wear, type = "b", legend = FALSE))
par(mfrow=c(1, 1), cex = 1)