gmData-class             package:gRbase             R Documentation

_C_l_a_s_s "_g_m_D_a_t_a" _g_r_a_p_h_i_c_a_l _m_e_t_a _d_a_t_a

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

     A common class for representing data. No matter the actual
     representation of data, the important characteristics are
     contained in a graphical metadata object.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects can be created by calls of the form 'new("gmData",
     varNames, varTypes, numberLevels, latent, valueLabels,
     observations)'.

     A 'gmData' object contains the abstraction of data into a meta
     data object including variable names and types etc. However, the
     actual data might not be present or may be represented by a
     reference to data, such as a database file. Also, it may be
     possible to work without data, which may be valuable if the point
     of interest is in the model alone. Separating the specification of
     the variables from data has the benefit, that some properties of a
     model can be investigated without any reference to data, for
     example decomposability and collapsibility.

_S_l_o_t_s:

     '_d_e_s_c_r_i_p_t_i_o_n': Object of class '"data.frame"' containing one row
          for each variable and a column for each property of the
          variables. The properties include the variable name, the
          number of levels (for discrete variables), whether the
          variable is latent or not, and the variable type. The
          description may be extended by adding columns.  

     '_v_a_l_u_e_L_a_b_e_l_s': Object of class '"vector"' giving the names of the
          levels of the discrete variables. 

     '_o_b_s_e_r_v_a_t_i_o_n_s': Object of class '"dataOrNULL"' containing the
          data, a pointer to data or NULL if no data are used. 

_M_e_t_h_o_d_s:

     _c_o_e_r_c_e 'signature(from = "data.frame", to = "gmData")': Create
          gmData object from a data.frame. 

     _c_o_e_r_c_e 'signature(from = "table", to = "gmData")': Create gmData
          object from a table. 

     _c_o_e_r_c_e 'signature(from = "array", to = "gmData")': Create gmData
          object from an array. 

     _d_e_s_c_r_i_p_t_i_o_n 'signature(x = "gmData")': Extract the description
          slot from a gmData object. 

     _d_e_s_c_r_i_p_t_i_o_n<- 'signature(x = "gmData")': Replace the description
          slot from a gmData object. 

     _d_y_n_a_m_i_c._G_r_a_p_h 'signature(object = "gmData")': ... 

     _i_n_i_t_i_a_l_i_z_e 'signature(.Object = "gmData")': Creation of a gmData
          object. 

     _l_a_t_e_n_t 'signature(x = "gmData")': Extract the column "latent" from
          the description slot from a gmData object. 

     _l_a_t_e_n_t<- 'signature(x = "gmData")': Replace the column "latent"
          from the description slot from a gmData object. 

     _n_u_m_b_e_r_L_e_v_e_l_s 'signature(x = "gmData")': Extract the column
          "numberLevels" from the description slot from a gmData
          object. 

     _n_u_m_b_e_r_L_e_v_e_l_s<- 'signature(x = "gmData")': Replace the column
          "numberLevels" from the description slot from a gmData
          object. 

     _o_b_s_e_r_v_a_t_i_o_n_s 'signature(x = "gmData")': Extract the observations
          slot from a gmData object. 

     _o_b_s_e_r_v_a_t_i_o_n_s<- 'signature(x = "gmData")': Replace the observations
          slot from a gmData object. 

     _s_h_o_w 'signature(object = "gmData")': Print method for gmData
          object. 

     _v_a_l_u_e_L_a_b_e_l_s 'signature(x = "gmData")': Extract the valueLabels
          slot from a gmData object. 

     _v_a_l_u_e_L_a_b_e_l_s<- 'signature(x = "gmData")': Replace the valueLabels
          slot from a gmData object. 

     _v_a_r_N_a_m_e_s 'signature(x = "gmData")': Extract the column "varNames"
          from the description slot from a gmData object.  

     _v_a_r_N_a_m_e_s<- 'signature(x = "gmData")': Replace the column
          "varNames" from the description slot from a gmData object. 

     _v_a_r_T_y_p_e_s 'signature(x = "gmData")': Extract the column "varTypes"
          from the description slot from a gmData object. 

     _v_a_r_T_y_p_e_s<- 'signature(x = "gmData")': Replace the column
          "varTypes" from the description slot from a gmData object. 

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

     Sren Hjsgaard, sorenh@agrsci.dk, 
      Claus Dethlefsen, dethlef@math.aau.dk

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

     ~put references to the literature/web site here ~

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

     'demo(gmData)'

