BabyECG              package:wavethresh              R Documentation

_P_h_y_s_i_o_l_o_g_i_c_a_l _d_a_t_a _t_i_m_e _s_e_r_i_e_s.

_D_e_s_c_r_i_p_t_i_o_n:

     Two linked medical time series containing 2048 observations
     sampled every 16 seconds recorded from 21:17:59 to 06:27:18. Both
     these time series were recorded from the same 66 day old infant by
     Prof. Peter Fleming, Dr Andrew Sawczenko and Jeanine Young of the
     Institute of Child Health, Royal Hospital for Sick Children,
     Bristol. 'BabyECG', is a record of the infant's heart rate (in
     beats per minute). BabySS is a record of the infant's sleep state
     on a scale of 1 to 4 as determined by a trained expert monitoring
     EEG (brain) and EOG (eye-movement). The sleep state codes are
     1=quiet sleep, 2=between quiet and active sleep, 3=active sleep,
     4=awake.

_F_o_r_m_a_t:

     The 'BabyECG' time series is a nice example of a non-stationary
     time series whose spectral (time-scale) properties vary over time.
     The function 'ewspec' can be used to anaylse this time series to
     inspect the variation in the power of the series over time and
     scales. 

     The 'BabySS' time series is a useful independent time series that
     can be associated with changing power in the 'BabyECG' series. See
     the discussion in Nason, von Sachs and Kroisandt.

_R_E_L_E_A_S_E:

     Version 3.9 Copyright Guy Nason 1998

_S_E_E _A_L_S_O:

     'ewspec'

_E_X_A_M_P_L_E_S:

     # # Plot the BabyECG data with BabySS overlaid

     #

     # Note the following code does some clever scaling to get the two

     # time series overlaid.

     #

     myhrs <- c(22, 23, 24, 25, 26, 27, 28, 29, 30)

     mylab <- c("22", "23", "00", "01", "02", "03", "04", "05", "06")

     initsecs <- 59 + 60 * (17 + 60 * 21)

     mysecs <- (myhrs * 3600)

     secsat <- (mysecs - initsecs)/16

     mxy <- max(BabyECG)

     mny <- min(BabyECG)

     ro <- range(BabySS)

     no <- ((mxy - mny) * (BabySS - ro[1]))/(ro[2] - ro[1]) + mny

     rc <- 0:4

     nc <- ((mxy - mny) * (rc - ro[1]))/(ro[2] - ro[1]) + mny

     plot(1:length(BabyECG), BabyECG, xaxt = "n", type = "l", xlab = 

     "Time (hours)", ylab = "Heart rate (beats per minute)")

     lines(1:length(BabyECG), no, lty = 3)

     axis(1, at = secsat, labels = mylab)

     axis(4, at = nc, labels = as.character(rc))

     #

     # Sleep state is the right hand axis

     # #

_S_o_u_r_c_e:

     Institute of Child Health, Royal Hospital for Sick Children,
     Bristol.

_R_e_f_e_r_e_n_c_e_s:

     Nason, G.P., von Sachs, R. and Kroisandt, G. (1998). Wavelet
     processes and adaptive estimation of the evolutionary wavelet
     spectrum. _Technical Report_, Department of Mathematics University
     of Bristol/ Fachbereich Mathematik, Kaiserslautern.

