\Header{beavers}{Body Temperature Series of Two Beavers}
\alias{beaver1}{beavers}
\alias{beaver2}{beavers}
\keyword{datasets}{beavers}
\begin{Description}\relax
Reynolds (1994) describes a small part of a study of the long-term
temperature dynamics of beaver \emph{Castor canadensis} in
north-central Wisconsin.  Body temperature was measured by telemetry
every 10 minutes for four females, but data from a one period of
less than a day for each of two animals is used there.\end{Description}
\begin{Usage}
\begin{verbatim}data(beavers)\end{verbatim}
\end{Usage}
\begin{Format}\relax
The \code{beaver1} data frame has 114 rows and 4 columns on body
temperature measurements at 10 minute intervals.

The \code{beaver2} data frame has 100 rows and 4 columns on body
temperature measurements at 10 minute intervals.

The variables are as follows:
\describe{
\item[day] Day of observation (in days since the beginning of
1990), December 12--13 (\code{beaver1}) and November 3--4
(\code{beaver2}).
\item[time] Time of observation, in the form \code{0330} for
3:30am
\item[temp] Measured body temperature in degrees Celsius.
\item[activ] Indicator of activity outside the retreat.
}\end{Format}
\begin{Note}\relax
The observation at 22:20 is missing in \code{beaver1}.\end{Note}
\begin{Source}\relax
P. S. Reynolds (1994) Time-series analyses of beaver body
temperatures.  Chapter 11 of Lange, N., Ryan, L., Billard, L.,
Brillinger, D., Conquest, L. and Greenhouse, J. eds (1994)
\emph{Case Studies in Biometry.}
New York: John Wiley and Sons.\end{Source}
\begin{Examples}
\begin{ExampleCode}
data(beavers)

(yl <- range(beaver1$temp, beaver2$temp))

beaver.plot <- function(bdat, ...) {
  nam <- deparse(substitute(bdat))  
  attach(bdat)
  # Hours since start of day:
  hours <- time %/% 100 + 24*(day - day[1]) + (time %% 100)/60
  plot (hours, temp, type = "l", ...,
        main = paste(nam, "body temperature"))
  abline(h = 37.5, col = "gray", lty = 2)
  is.act <- activ == 1
  points(hours[is.act], temp[is.act], col = 2, cex = .8)
}
op <- par(mfrow = c(2,1), mar = c(3,3,4,2), mgp = .9* 2:0)
 beaver.plot(beaver1, ylim = yl)
 beaver.plot(beaver2, ylim = yl)
par(op)
\end{ExampleCode}
\end{Examples}

