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.
The observation at 22:20 is missing.
beav1 data frame has 114 rows and 4 columns.
This data frame contains the following columns:
- Day of observation (in days since the beginning of 1990), December 12--13.
Time of observation, in the form
- Measured body temperature in degrees Celsius.
- Indicator of activity outside the retreat.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
beav1 <- within(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) rm(temp, activ)