Milk                  package:nlme                  R Documentation

Protein content of cows' milk

Description:

     The 'Milk' data frame has 1337 rows and 4 columns.

Format:

     This data frame contains the following columns:

     protein a numeric vector giving the protein content of the milk.

     Time a numeric vector giving the time since calving (weeks).

     Cow an ordered factor giving a unique identifier for each cow.

     Diet a factor with levels 'barley',  'barley+lupins', and 
          'lupins' identifying the diet for each cow.


Details:

     Diggle, Liang, and Zeger (1994) describe data on the protein
     content of cows' milk in the weeks following calving.  The cattle
     are grouped according to whether they are fed a diet with barley
     alone, with barley and lupins, or with lupins alone.

Source:

     Diggle, Peter J., Liang, Kung-Yee and Zeger, Scott L. (1994),
     _Analysis of longitudinal data_, Oxford University Press, Oxford.

