BodyWeight               package:nlme               R Documentation

_R_a_t _w_e_i_g_h_t _o_v_e_r _t_i_m_e _f_o_r _d_i_f_f_e_r_e_n_t _d_i_e_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     The 'BodyWeight' data frame has 176 rows and 4 columns.

_F_o_r_m_a_t:

     This data frame contains the following columns:

     _w_e_i_g_h_t a numeric vector giving the body weight of the rat (grams).

     _T_i_m_e a numeric vector giving the time at which the measurement is
          made (days).

     _R_a_t an ordered factor with levels '2' < '3' < '4' < '1' < '8' <
          '5' < '6' < '7' < '11' < '9' < '10' < '12' < '13' < '15' <
          '14' < '16' identifying the rat whose weight is measured.

     _D_i_e_t a factor with levels '1' to '3' indicating the diet that the
          rat receives.

_D_e_t_a_i_l_s:

     Hand and Crowder (1996) describe data on the body weights of rats
     measured over 64 days.  These data also appear in Table 2.4 of
     Crowder and Hand (1990).  The body weights of the rats (in grams)
     are measured on day 1 and every seven days thereafter until day
     64, with an extra measurement on day 44. The experiment started
     several weeks before ``day 1.''  There are three groups of rats,
     each on a different diet.

_S_o_u_r_c_e:

     Pinheiro, J. C. and Bates, D. M. (2000), _Mixed-Effects Models in
     S and S-PLUS_, Springer, New York. (Appendix A.3)

     Crowder, M. and Hand, D. (1990), _Analysis of Repeated Measures_,
     Chapman and Hall, London.

     Hand, D. and Crowder, M. (1996), _Practical Longitudinal Data
     Analysis_, Chapman and Hall, London.

_E_x_a_m_p_l_e_s:

     data(BodyWeight)

