iqr                   package:LPE                   R Documentation

_I_n_t_e_r-_q_u_a_r_t_i_l_e _r_a_n_g_e

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

     Finds inter-quartile range of the data = {75th percentile - 25th
     percentile}.

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

       iqr(x)

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

       x: x is a vector for which IQR has to be found.

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

     Returns a numeric value representing the difference of 75th
     percentile  and 25th percentile of the vector. It is used for
     normalization across  the chips - basic assumption is that net
     differential expression of  the middle half of the genes in
     microarray experiment is zero, which  is conservative assumption
     as typically only 5-10 differential expression.

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

     J.K. Lee and M.O.Connell(2003). _An S-Plus library for the
     analysis of differential expression_. In The Analysis of Gene
     Expression Data: Methods and Software. Edited by G. Parmigiani, ES
     Garrett, RA Irizarry ad SL Zegar. Springer, NewYork.

     Jain et. al. (2003) _Local pooled error test for identifying
     differentially expressed genes with a small number of replicated
     microarrays_, Bioinformatics, 1945-1951.

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

     'lpe'

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

       library(LPE)
       # Loading the LPE library
      
       iqr(1:5) 

