nlme (version 3.1-130)

BodyWeight: Rat weight over time for different diets

Description

The BodyWeight data frame has 176 rows and 4 columns.

Format

This data frame contains the following columns:

Source

Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S and S-PLUS, Springer, New York. (Appendix A.3) Crowder, M. and Hand, D. (1990), Analysis of Repeated Measures, Chapman and Hall, London. Hand, D. and Crowder, M. (1996), Practical Longitudinal Data Analysis, Chapman and Hall, London.

Details

Hand and Crowder (1996) describe data on the body weights of rats measured over 64 days. These data also appear in Table 2.4 of Crowder and Hand (1990). The body weights of the rats (in grams) are measured on day 1 and every seven days thereafter until day 64, with an extra measurement on day 44. The experiment started several weeks before ``day 1.'' There are three groups of rats, each on a different diet.