beav1 {MASS} | R Documentation

## Body Temperature Series of Beaver 1

### 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

    data(beav1)

### Format

The `beav1` data frame has 114 rows and 4 columns. This data frame contains the following columns:

`day`
  Day of observation (in days since the beginning of 1990), December 12-13.
`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

### Note

The observation at 22:20 is missing.

### 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

`beav2`

### Examples

    library(ts)
    attach(beav1)
    beav1$hours <- 24*(day-346) + trunc(time/100) + (time%%100)/60
    plot(beav1$hours, beav1$temp, type="l", xlab="time",
       ylab="temperature", main="Beaver 1")
    usr <- par("usr"); usr[3:4] <- c(-0.2, 8); par(usr=usr)
    lines(beav1$hours, beav1$activ, type="s", lty=2)
    temp <- ts(c(beav1$temp[1:82], NA, beav1$temp[83:114]), start=9.5, frequency=6)
    activ <- ts(c(beav1$activ[1:82], NA, beav1$activ[83:114]), start=9.5, frequency=6)

    acf(temp[1:53])
    acf(temp[1:53], type = "partial")
    ar(temp[1:53])
    act <- c(rep(0, 10), activ)
    X <- cbind(1, act = act[11:125], act1 = act[10:124],
              act2 = act[9:123], act3 = act[8:122])
    alpha <- 0.80
    stemp <- as.vector(temp - alpha*lag(temp, -1))
    sX <- X[-1, ] - alpha * X[-115,]
    beav1.ls <- lm(stemp ~ -1 + sX, na.action = na.omit)
    summary(beav1.ls, cor = FALSE)
    detach("beav1"); rm(temp, activ)

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