De-inking of newsprint
De-inking of newsprint
A data frame with 27 observations on the following 3 variables.
alkaliamount of alkali in the solution
hardnesshardness of the water - an ordered factor
with levels 50 < 150 < 250
brighta measure of brightness
One step of recycling newsprint is to "de-ink" the newsprint, that is to remove the ink. The brightness of the paper pulp after a de-inking process is a measure of how well the process to remove the ink worked.
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
str(deink)
xtabs(~ alkali + hardness, deink)
dotplot(hardness ~ bright, deink, groups = alkali,
auto.key = list(columns = 3, lines = TRUE),
type = c("p","a"), aspect = 'xy',
xlab = "Brightness by amount of alkali",
ylab = "Hardness of the water")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.