sarea {EngrExpt} | R Documentation |
Surface area of silica
Description
Measurements of the surface area () of three batches of
silica as performed by four different lab technicians.
Format
A data frame with 12 observations on the following 3 variables.
batch
a factor with levels
a
,b
andc
tech
a factor with levels
A
,B
,C
andD
sarea
the surface area in
as measured by the lab technician on a sample from the batch
References
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
Examples
str(sarea)
xtabs(sarea ~ batch + tech, sarea)
dotplot(reorder(tech, sarea) ~ sarea, sarea,
groups = batch, type = c("p","a"), aspect = "xy",
ylab = "Technician",
xlab = expression("Measured surface area " * (m^2/g) *
" of silica batches"),
auto.key = list(columns = 3, lines = TRUE)
)
[Package EngrExpt version 0.1-8 Index]