vstat               package:quantchem               R Documentation

_V_a_r_i_a_b_i_l_i_t_y _s_t_a_t_i_s_t_i_c_s _o_f _q_u_a_n_t_i_t_a_t_i_v_e _a_n_a_l_y_s_i_s _r_e_s_u_l_t_s

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

     Estimate error propagation of results (inter- and intra-day,
     inter- and intra-batch etc.)

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

     vstat(x, ...)

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

       x: a data frame of results. Each column contain one serie of
          results

     ...: optionally, more data frames, if additional factor is taking
          into account 

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

     This function performs one-way or two-way ANOVA on given results
     and prints summary in the usable way. If we are checking
     variability only between and within one kind of series (days,
     batches), we construct a data frame with a result sets in its
     columns and call this function on such data.frame. In this case,
     we get variability analysis of between-series and within-series.
     If we want to check variability additionally for example between
     weeks, we group results in data frames for each week and call the
     function on all data frames. This will summarize error propagation
     concerning series and groups.

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

     The ANOVA object is returned, containing additional columns:

 Percent: Percentage indication of error propagation (total sum of
          squares is 100 percent

      SD: Standard deviation (square root of Mean Sq) 

     RSD: Relative standard deviation (coefficient of variation) 


     There are also additional rows - lowest row gives overall (total)
     error, and if function is called on multiple data-frames, a row
     containing variability between all series (sum of within-groups
     and between-groups) is given.

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

     Lukasz Komsta

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

     'dstat'

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

     set.seed(1234)
     week1 = data.frame(mon=rnorm(6),tue=rnorm(6),wed=rnorm(6),thu=rnorm(6),fri=rnorm(6))
     week2 = data.frame(mon=rnorm(6),tue=rnorm(6),wed=rnorm(6),thu=rnorm(6),fri=rnorm(6))
     week3 = data.frame(mon=rnorm(6),tue=rnorm(6),wed=rnorm(6),thu=rnorm(6),fri=rnorm(6))
     week4 = data.frame(mon=rnorm(6),tue=rnorm(6),wed=rnorm(6),thu=rnorm(6),fri=rnorm(6))
     week1=week1+15;week2=week2+15;week3=week3+15;week4=week4+15
     vstat(week1)
     vstat(week1,week2,week3,week4)

