lowFilter-methods            package:xps            R Documentation

_L_o_w_e_r _T_h_r_e_s_h_o_l_d _F_i_l_t_e_r

_D_e_s_c_r_i_p_t_i_o_n:

     This method initializes the Lower Threshold Filter. The 'cutoff'
     value defines the lower threshold for allowed expression levels.
     If e.g. the number of samples lower than this cutoff value is
     greater than 'parameter' then the corresponding dataframe row is
     flagged, i.e. 'flag = 0'. 
      The Lower Threshold Filter flags all rows with: 'flag =
     (sum(expression[i] >= cutoff) >= parameter)'

     _Usage_

     'lowFilter(object)' 
      'lowFilter(object, value)<-'

_A_r_g_u_m_e_n_t_s:

  object: object of class 'PreFilter'.

   value: character vector 'c(cutoff, parameter, condition)'.

_D_e_t_a_i_l_s:

     The method 'lowFilter' initializes the following parameters:

         'cutoff':     the lower threshold level for the filter.
         'parameter':  this value depends on the 'condition' used:
         'condition':  'condition="samples"':    number of samples (default):
                       'condition="percent"':    percent of samples.
                       'condition="mean"':       mean value of samples.
                       'condition="percentile"': percentile of samples.

_V_a_l_u_e:

     An initialized 'PreFilter' object.

_A_u_t_h_o_r(_s):

     Christian Stratowa

_E_x_a_m_p_l_e_s:

     prefltr <- PreFilter()
     lowFilter(prefltr) <- c(4.0,3,"samples")
     str(prefltr)

