REAR                  package:agce                  R Documentation

_F_i_t _a _a_u_t_o_r_e_g_r_e_s_s_i_v_e _m_o_d_e_l _w_i_t_h _r_a_n_d_o_m _e_r_r_o_r_s

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

     This function fits two different models using the nlme library and
     then compares them using a likelihood ratio test. The first model
     is an autoregressive random errors model with a linear mean
     assuming different slope in each group. The second model is an
     autoregressive random errors model with a linear mean assuming
     same slope in each group.

_U_s_a_g_e:

     REAR(data,time)

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

    data: The data matrix or data frame, where the first column
          correspond to the group id, the second to the animal id, the
          remaining columns are the measurement at each time. 

    time: A vector of numeric values corresponding to the time points
          at which the measurements were effectued.

_D_e_t_a_i_l_s:

     The data are reshaped in a longitudinal dataset and then the
     models are fit using the lme function of the nlme library.

_V_a_l_u_e:

     Chi: The value of the Chisquare test used to  test the hypothesis
          of equal slopes

      df: The degrees of freedom for the Chisquare test

       p: The p-value associated to the Chisquare test

sum.fit.full: The summary on the fit of the full model

std.fit.reduced: The summary on the fit of the reduced model

_A_u_t_h_o_r(_s):

     Raphael Gottardo

_R_e_f_e_r_e_n_c_e_s:

     Daniel F. Heitjan, Andrea Manni and Richard J. Santen Statistical
     Analysis of in Vivo Tumor Growth Experiments Cancer Research
     53:6042-6050, 1993.

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

     data(Bt20)
     REAR(Bt20,c(0,3,7,10,14,16))

