EngrExpt (version 0.1-6)

adhesion: Adhesive qualities of a lens coating

Description

These data are from two experiments to examine the effect of pH and catalyst on the adhesive qualities of a lens coating. In the adhesion data ten samples were made and tested at each of three pH levels. In the adhesion2 data five samples were made and tested at each of six combinations of pH and catalyst.

code

adhesion2

describe

• cat
  a factor with levels A B
• pH
  a numeric vector
• adhesion
  a numeric vector

References

Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)

Examples

str(adhesion)
xtabs(~ pH, adhesion)
xyplot(adhesion ~ pH, adhesion, ylab = "Adhesion of a lens coating",
       xlab = "pH", type = c("g", "p", "a"))
dotplot(as.factor(pH) ~ adhesion, adhesion, ylab = "pH", type =
       c("p","a"), xlab = "Adhesion of a lens coating")
str(adhesion2)
xtabs(~ cat + pH, adhesion2)
dotplot(as.factor(pH) ~ adhesion, adhesion2, groups = cat,
        type = c("p","a"), ylab = "pH",
        auto.key = list(space = "right", lines = TRUE,
                        title = "Catalyst"))