aggregator              package:Biobase              R Documentation

_A _S_i_m_p_l_e _C_l_a_s_s _f_o_r _A_g_g_r_e_g_a_t_o_r_s

_D_e_s_c_r_i_p_t_i_o_n:

     A class of objects designed to help aggregate calculations over an
     iterative computation. The aggregator consists of three objects.
     An environment to hold the values. A function that sets up an
     initial value the first time an object is seen. An aggregate
     function that increments the value of an object seen previously.

_D_e_t_a_i_l_s:

     This class is used to help aggregate different values over
     function calls. A very simple example is to use leave one out
     cross-validation for prediction. At each stage we first perform
     feature selection and then cross-validate. To keep track of how
     often each feature is selected we can use an aggregator. At the
     end of the cross-validation we can extract the names of the
     features chosen from 'aggenv'.

_C_r_e_a_t_i_n_g _O_b_j_e_c_t_s:

     'new('aggregator', aggenv  = [environment], initfun = [function],
     aggfun  = [function])'

_S_l_o_t_s:

     '_a_g_g_e_n_v': Object of class 'environment', holds the values between
          iterations

     '_i_n_i_t_f_u_n': Object of class 'function' specifies how to initialize
          the value for a name the first time it is encountered

     '_a_g_g_f_u_n': Object of class 'function' used to increment (or perform
          any other function) on a name

_M_e_t_h_o_d_s:

     '_a_g_g_e_n_v(_a_g_g_r_e_g_a_t_o_r)': Used to access the environment of the
          aggregator

     '_a_g_g_f_u_n(_a_g_g_r_e_g_a_t_o_r)': Used to access the function that aggregates

     '_i_n_i_t_f_u_n(_a_g_g_r_e_g_a_t_o_r)': Used to access the initializer function

_S_e_e _A_l_s_o:

     'Aggregate'