R: Body Temperature Series of Beaver 2

Body Temperature Series of Beaver 2

Arguments

`day`	Day of observation (in days since the beginning of 1990), November 3-4.
`time`	Time of observation, in the form `0330` for 3.30am
`temp`	Measured body temperature in degrees Celcius
`activ`	Indicator of activity outside the retreat

SUMMARY

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

DATA DESCRIPTION

Reynolds (1994) describes a small part of a study of the long-term temperature dynamics of beaver 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.

This data frame contains the following columns:

SOURCE

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) Case Studies in Biometry. New York: John Wiley and Sons.

Examples

### Not usable in R
attach(beav2)
beav2$hours <- 24*(day-307) + trunc(time/100) + (time%%100)/60
plot(beav2$hours, beav2$temp, type="l", xlab="time", 
   ylab="temperature", main="Beaver 2")
usr <- par("usr"); usr[3:4] <- c(-0.2, 8); par(usr=usr)
lines(beav2$hours, beav2$activ, type="s", lty=2)

attach(beav2)
temp <- rts(temp, start=8+2/3, frequency=6, units="hours")
activ <- rts(activ, start=8+2/3, frequency=6, units="hours")
acf(temp[activ==0]); acf(temp[activ==1]) # also look at PACFs
ar(temp[activ==0]); ar(temp[activ==1])

arima.mle(temp, xreg=rep(1, length(temp)), model=list(ar=0.75))
arima.mle(temp, xreg=cbind(1, activ), model=list(ar=0.75))

beav2.lme <- lme(temp ~ activ, cluster = ~rep(1,100), 
     data=beav2,  serial.structure="ar1", est.method="ML")
summary(beav2.lme)