This is a database that contains information on the inside diameter of piston rings. Piston rings are manufactured for an automobile engine that are produced through a forging process. This process is considered "in control" and is measured on 25 samples, each of size 5.
Format
A data frame with 200 observations on the following 3 variables.
- diameter
A numeric vector.
- sample
Sample ID
- trial
Trial sample indicator (
TRUE/FALSE)
References
Montgomery, D.C. (1991) Introduction to Statistical Quality Control, 2nd ed, New York, John Wiley & Sons, pp. 206--213
Examples
data(pistonrings)
attach(pistonrings)
#> The following objects are masked from orangejuice:
#>
#> sample, trial
summary(pistonrings)
#> diameter sample trial
#> Min. :73.97 Min. : 1.00 Mode :logical
#> 1st Qu.:74.00 1st Qu.:10.75 FALSE:75
#> Median :74.00 Median :20.50 TRUE :125
#> Mean :74.00 Mean :20.50
#> 3rd Qu.:74.01 3rd Qu.:30.25
#> Max. :74.04 Max. :40.00
boxplot(diameter ~ sample)
plot(sample, diameter, cex=0.7)
lines(tapply(diameter,sample,mean))
detach(pistonrings)