Weights: Data from a weight-lifting program
In SASmixed: Data sets from "SAS System for Mixed Models"

The Weights data frame has 399 rows and 5 columns.

This data frame contains the following columns:

strength: a numeric vector
Subject: a factor with levels 1 to 21
Program: a factor with levels CONT (continuous repetitions and weights), RI (repetitions increasing) and WI (weights increasing)
Subj: an ordered factor indicating the subject on which the measurement is made
Time: a numeric vector indicating the time of the measurement

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 3.2(a)).

str(Weights)
if (require("lme4", quietly = TRUE, character = TRUE)) {
  options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
  ## compare with output 3.1, p. 91
  print(fm1Weight <- lmer(strength ~ Program * Time + (1|Subj), Weights))
  print(anova(fm1Weight))
  print(fm2Weight <- lmer(strength ~ Program * Time + (Time|Subj), Weights))
  print(anova(fm1Weight, fm2Weight))
## Not run: 
intervals(fm2Weight)
fm3Weight <- update(fm2Weight, correlation = corAR1())
anova(fm2Weight, fm3Weight)
fm4Weight <- update(fm3Weight, strength ~ Program * (Time + I(Time^2)),
                    random = ~Time|Subj)
summary(fm4Weight)
anova(fm4Weight)
intervals(fm4Weight)

## End(Not run)
}