beav1: Body Temperature Series of Beaver 1

Description Usage Format Note Source References See Also Examples

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

1

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 Celsius.

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

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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)

Example output

Call:
ar(x = temp[1:53])

Coefficients:
     1  
0.8222  

Order selected 1  sigma^2 estimated as  0.01011

Call:
lm(formula = stemp ~ -1 + sX, na.action = na.omit)

Residuals:
     Min       1Q   Median       3Q      Max 
-0.21317 -0.04317  0.00683  0.05483  0.37683 

Coefficients:
       Estimate Std. Error t value Pr(>|t|)    
sX     36.85587    0.03922 939.833  < 2e-16 ***
sXact   0.25400    0.03930   6.464 3.37e-09 ***
sXact1  0.17096    0.05100   3.352  0.00112 ** 
sXact2  0.16202    0.05147   3.148  0.00215 ** 
sXact3  0.10548    0.04310   2.448  0.01605 *  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 0.08096 on 104 degrees of freedom
  (5 observations deleted due to missingness)
Multiple R-squared:  0.9999,	Adjusted R-squared:  0.9999 
F-statistic: 1.81e+05 on 5 and 104 DF,  p-value: < 2.2e-16

MASS documentation built on May 3, 2021, 5:08 p.m.

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