beav2 {MASS} | 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.

### Usage

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 Celcius
`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.

### See Also

`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))
library(nlme)
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)

[Package

*MASS* version 7.2-23

Index]