SASmixed (version 1.0-4)

Weights: Data from a weight-lifting program

Description

The Weights data frame has 399 rows and 5 columns.

Format

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

Source

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)).

Examples

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)
}