Strengths of metal bonds

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Description

The Bond data frame has 21 rows and 3 columns of data on the strength required to break metal bonds according to the metal and the ingot.

Format

This data frame contains the following columns:

pressure

a numeric vector of pressures required to break the bond

Metal

a factor with levels c, i and n indicating the metal involved (copper, iron or nickel).

Ingot

an ordered factor indicating the ingot of the composition material.

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 1.2.4).

Mendenhall, M., Wackerly, D. D. and Schaeffer, R. L. (1990), Mathematical Statistics, Wadsworth (Exercise 13.36).

Examples

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str(Bond)
options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
if (require("lme4", quietly = TRUE, character = TRUE)) {
  ## compare with output 1.1 on p. 6
  print(fm1Bond <- lmer(pressure ~ Metal + (1|Ingot), Bond))
  print(anova(fm1Bond))
}