veneer {WWGbook} | R Documentation |
The Dental Veneer data were collected by researchers at the University of Michigan Dental School, in a study investigating the impact of veneer placement on subsequent gingival (gum) health among adult patients (Ocampo, 2005).
data(veneer)
A data frame with 110 observations on the following 7 variables.
Ocampo, J., Data taken from M.S. Thesis, Effect of Porcelain Laminate Contour on Gingival Inflammation, University of Michigan School of Dentistry, 2005
West, B., Welch, K. & Galecki, A, Linear Mixed Models: A Practical Guide Using Statistical Software, Chapman Hall / CRC Press, first edition, 2006.
attach(veneer) #### Figure 7.2: Raw GCF values for each tooth vs. time, by patient. Panels are ordered by patient age. age.f <- factor(age) time.f <- factor(time) tooth.f <- factor(tooth) veneer <- data.frame(veneer,age.f, time.f, tooth.f) sort(age.f) library(lattice) # Load the library for trellis graphics. # Load the nlme library, which is required for the # plots below as well as for subsequent models. library(nlme) veneer.g1 <- groupedData(gcf ~ time | tooth.f, outer = ~ age.f, data = veneer) plot(veneer.g1, display = "tooth", outer = TRUE, aspect = 2, key = FALSE, xlab = "time", ylab = "GCF", main="Panels are ordered by patient age." ,layout=c(4,3))