

beav1(MASS)                                  R Documentation

_B_o_d_y _T_e_m_p_e_r_a_t_u_r_e _S_e_r_i_e_s _o_f _B_e_a_v_e_r _1

_D_e_s_c_r_i_p_t_i_o_n_:

     The `beav1' data frame has 114 rows and 4 columns on
     body temperature measurements at 10 minute intervals.

_A_r_g_u_m_e_n_t_s_:

     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

_F_o_r_m_a_t_:

     Reynolds (1994) describes a small part of a study of
     the long-term temperature dynamics of beaver Castor
     canadensis in north-central Wisconsin.  Body tempera-
     ture 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:

_N_o_t_e_:

     The observation at 22:20 is missing.

_S_o_u_r_c_e_:

     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 Green-
     house, J. eds (1994) Case Studies in Biometry.  New
     York: John Wiley and Sons.

_S_e_e _A_l_s_o_:

     `beav2'

_E_x_a_m_p_l_e_s_:

     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)

