meanT                package:statmod                R Documentation

_M_e_a_n _t-_S_t_a_t_i_s_t_i_c _B_e_t_w_e_e_n _T_w_o _G_r_o_u_p_s _o_f _G_r_o_w_t_h _C_u_r_v_e_s

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

     The mean-t statistic of the distance between two groups of growth
     curves.

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

     meanT(y1, y2)

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

      y1: matrix of response values for the first group, with a row for
          each individual and a column for each time. Missing values
          are allowed.

      y2: matrix of response values for the second group.  Must have
          the same number of columns as 'y1'. Missing values are
          allowed.

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

     This function computes the pooled two-sample t-statistic between
     the response values at each time, and returns the mean of these
     values weighted by the degrees of freedom. This function is used
     by 'compareGrowthCurves'.

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

     numeric vector of length one containing the mean t-statistic.

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

     Gordon Smyth

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

     'compareGrowthCurves', 'compareTwoGrowthCurves'

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

     y1 <- matrix(rnorm(4*3),4,3)
     y2 <- matrix(rnorm(4*3),4,3)
     meanT(y1,y2)

     data(PlantGrowth)
     compareGrowthCurves(PlantGrowth$group,as.matrix(PlantGrowth$weight))
     # Can make p-values more accurate by nsim=10000

