wtloss                 package:MASS                 R Documentation

_W_e_i_g_h_t _L_o_s_s _D_a_t_a _f_r_o_m _a_n _O_b_e_s_e _P_a_t_i_e_n_t

_D_e_s_c_r_i_p_t_i_o_n:

     The data frame gives the weight, in kilograms, of an obese patient
     at 52 time points over an 8 month period of a weight
     rehabilitation programme.

_U_s_a_g_e:

     data(wtloss)

_F_o_r_m_a_t:

     This data frame contains the following columns:

     '_D_a_y_s' Time in days since the start of the programme.

     '_W_e_i_g_h_t' Weight in kilograms of the patient.

_S_o_u_r_c_e:

     Dr T. Davies, Adelaide.

_R_e_f_e_r_e_n_c_e_s:

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

_E_x_a_m_p_l_e_s:

     wtloss.fm <- nls(Weight ~ b0 + b1*2^(-Days/th),
         data = wtloss, start = list(b0=90, b1=95, th=120),
         trace = TRUE)

