logregtree             package:LogicReg             R Documentation

_F_o_r_m_a_t _o_f _c_l_a_s_s _l_o_g_r_e_g_t_r_e_e

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

     This help file contains a description of the format of class
     logregtree.

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

     logregtree()

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

     When storing trees, we number the location of the nodes using the
     following scheme (this is an example for a tree with at most 8
     _terminal_ nodes, but the generalization should be obvious):

                              1                        
                2                           3          
          4            5             6             7   
       8     9     10     11     12     13     14     15

     Each node may or may not be present in the current tree. If it is
     present, it can contain an operator (``and'' or ``or''), in which
     case it has to child nodes, or it can contain a variable, in which
     case the node is a terminal node. It is also possible that the
     node does not exist (as the user only specifies the maximum tree
     size, not the tree size that is actually fitted).

     Output files have one line for each node. Each line contains 5
     numbers:

        1.  the node number.

        2.  does this node contain an ``and'' (1), an ``or'' (2), a
           variable (3), or is the node empty (0).

        3.  if the node contains a variable, which one is it; e.g. if
           this number is 3 the node contains X3.

        4.  if the node contains a variable, does it contain the
           regular variable (0) or its complement (1)

        5.  is the node empty (0) or not (1) (this information is
           redundant with the second number) .inen -3

           *Example*

                                          AND                        
                                                                     
                                                                     
                        OR                            OR             
                                                                     
                                                                     
               OR               OR               X20            OR   
                                                                     
          X17      X12      X3      X13c                    X2      X1

           is represented as

           1  1   0  0  1
           2  2   0  0  1
           3  2   0  0  1
           4  2   0  0  1
           5  2   0  0  1
           6  3  20  0  1
           7  2   0  0  1
           8  3  17  0  1
           9  3  12  0  1
          10  3   3  0  1
          11  3  13  1  1
          12  0   0  0  0
          13  0   0  0  0
          14  3   2  0  1
          15  3   1  0  1

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

     An object of class logregtree is typically a substructure of an
     object of the class 'logregmodel'.  It will typically be the
     result of using the fitting function 'logreg'.  An object of class
     logictree has the following components: 

whichtree: the sequence number of the current tree within the model.

    coef: the coefficients of this tree.

   trees: a matrix (data.frame) with five columns; see below for the
          format.

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

     Ingo Ruczinski ingo@jhu.edu and Charles Kooperberg clk@fhcrc.org.

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

     Ruczinski I, Kooperberg C, LeBlanc ML (2003).  Logic Regression,
     _Journal of Computational and Graphical Statistics_, *12*,
     475-511.

     Ruczinski I, Kooperberg C, LeBlanc ML (2002).  Logic Regression -
     methods and software.  _Proceedings of the MSRI workshop on
     Nonlinear Estimation and Classification_ (Eds: D. Denison, M.
     Hansen, C. Holmes, B. Mallick, B. Yu), Springer: New York,
     333-344.

     Selected chapters from the dissertation of Ingo Ruczinski,
     available from <URL:
     http://bear.fhcrc.org/~ingor/logic/documents/myphd-logic.pdf>

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

     'logreg', 'plot.logregtree', 'print.logregtree', 'logregmodel'

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

     logregtree()       # displays this help file
     help(logregtree)   # equivalent

