| vitamin {EngrExpt} | R Documentation |
Calcium levels before and after vitamin supplement
A data frame with 49 observations on the following 3 variables.
treatmentA,
B and CbeforeafterPeter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
str(vitamin)
summary(vitamin)
show(plt1 <- xyplot(after ~ before, vitamin, groups = treatment,
auto.key = list(space = "right", title = "Formulation", lines = TRUE),
aspect = "iso",
type = c("g","p","smooth"),
xlab = "Calcium level before the vitamin",
ylab = "Calcium level after the vitamin"))
tmd(plt1, aspect = 1)
densityplot(~ I(after - before), vitamin, groups = treatment,
auto.key = list(columns = 3, lines = TRUE),
xlab = "Change in calcium level after taking vitamin")