beav1 {MASS} | R Documentation |
The beav1
data frame has 114 rows and 4 columns on body
temperature measurements at 10 minute intervals.
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 |
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:
The observation at 22:20 is missing.
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.
library(ts) data(beav1) 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=F) detach("beav1"); rm(temp, activ)