\HeaderA{Milk}{Protein content of cows' milk}{Milk}
\keyword{datasets}{Milk}
\begin{Description}\relax
The \code{Milk} data frame has 1337 rows and 4 columns.
\end{Description}
\begin{Format}\relax
This data frame contains the following columns:
\describe{
\item[protein] a numeric vector giving the protein content of the milk.

\item[Time] a numeric vector giving the time since calving (weeks).

\item[Cow] an ordered factor giving a unique identifier for each cow.

\item[Diet] a factor with levels
\code{barley}, 
\code{barley+lupins}, and 
\code{lupins} identifying the diet for each cow.

}
\end{Format}
\begin{Details}\relax
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.
\end{Details}
\begin{Source}\relax
Diggle, Peter J., Liang, Kung-Yee and Zeger, Scott L. (1994),
\emph{Analysis of longitudinal data}, Oxford University Press,
Oxford.
\end{Source}

