

balancedGrouped(nlme)                        R Documentation

_C_r_e_a_t_e _a _g_r_o_u_p_e_d_D_a_t_a _o_b_j_e_c_t _f_r_o_m _a _m_a_t_r_i_x

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

     Create a `groupedData' object from a data matrix.  This
     function can be used only with balanced data.  The
     opposite conversion, from a `groupedData' object to a
     `matrix', is done with `asTable'.

_U_s_a_g_e_:

     balancedGrouped(form, data, labels=NULL, units=NULL)

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

    form: A formula of the form `y ~ x | g' giving the name
          of the response, the primary covariate, and the
          grouping factor.

    data: A matrix or data frame containing the values of
          the response grouped according to the levels of
          the grouping factor (rows) and the distinct levels
          of the primary covariate (columns).  The `dim-
          names' of the matrix are used to construct the
          levels of the grouping factor and the primary
          covariate.

  labels: an optional list of character strings giving
          labels for the response and the primary covariate.
          The label for the primary covariate is named `x'
          and that for the response is named `y'.  Either
          label can be omitted.

   units: an optional list of character strings giving the
          units for the response and the primary covariate.
          The units string for the primary covariate is
          named `x' and that for the response is named `y'.
          Either units string can be omitted.

_V_a_l_u_e_:

     A balanced `groupedData' object.

_A_u_t_h_o_r_(_s_)_:

     Jose Pinheiro and Douglas Bates

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

     `groupedData', `isBalanced', `asTable'

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

     library(nlme)
     data(Orthodont)
     OrthoMat <- asTable( Orthodont )
     Orth2 <- balancedGrouped(distance ~ age | Subject, data = OrthoMat,
         labels = list(x = "Age",
                       y = "Distance from pituitary to pterygomaxillary fissure"),
         units = list(x = "(yr)", y = "(mm)"))
     Orth2[ 1:10, ]        ## check the first few entries

