beav2 R Documentation

## Body Temperature Series of Beaver 2

### 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.

```beav2
```

### Format

The `beav2` data frame has 100 rows and 4 columns. This data frame contains the following columns:

`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 Celsius.

`activ`

Indicator of activity outside the retreat.

### 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.

### References

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

`beav1`

### Examples

```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)

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

arima(temp, order = c(1,0,0), xreg = activ)
dreg <- cbind(sin = sin(2*pi*beav2\$hours/24), cos = cos(2*pi*beav2\$hours/24))
arima(temp, order = c(1,0,0), xreg = cbind(active=activ, dreg))

## IGNORE_RDIFF_BEGIN
library(nlme) # for gls and corAR1
beav2.gls <- gls(temp ~ activ, data = beav2, corr = corAR1(0.8),
method = "ML")
summary(beav2.gls)
summary(update(beav2.gls, subset = 6:100))
detach("beav2"); rm(temp, activ)
## IGNORE_RDIFF_END
```