contrMatRatio            package:mratios            R Documentation

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

     Creates numerator and denominator contrast matrices for some
     common multiple comparison and trend test problems.  These
     matrices are internally used by the sci.ratio and simtest.ratio
     functions. The contrMatRatio function is a modification of the
     function contrMat (multcomp).

     Whether the given definitions of contrast matrices for trend test
     problems in terms of ratios make sense and how they are to be
     interpreted is to be discussed.

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

     contrMatRatio(n, type = "Tukey", base = 1)

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

       n: integer vector of sample sizes 

    type: the type of multiple contrasts 

             *  *"Dunnett":* many to one comparisons, with the control
                group in the denominator

             *  *"Tukey":* all-pair comparisons 

             *  *"Sequen":* comparison of consecutive groups, where the
                groups of lower order is the denominator 

             *  *"AVE":* comparison of each group with average of all
                others, where the average is taken as denominator

             *  *"GrandMean":* comparison of each group with grand mean
                of all groups, where the grand mean is taken as
                denominator

             *  *"Changepoint":* ratio of averages of groups of higher
                order divided by averages of groups of lower order 

             *  *"Marcus":* Marcus contrasts defined for ratios 

             *  *"McDermott":* McDermott contrasts for ratios 

             *  *"Williams":* Williams contrasts for ratios 

             *  *"UmbrellaWilliams":* Umbrella-protected Williams
                contrasts for ratios, i.e.a sequence of Williams-type
                contrasts with groups of higher order stepwise omitted 


    base: a single integer specifying the control (i.e. denominator)
          group for "Dunnett"-type contrasts for calculating the ratios
          to the control 

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

     This is a simple adaption of the contrMat function in the package
     multcomp for ratio hypotheses.

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

     A list containing: 

   numC : the (named) numerator contrast where rows correspond to
          contrasts 

   denC : the (named) denominator contrast where rows correspond to
          contrasts 

 rnames : a character vector with names of the contrasts 

     and the type of contrast as attr.

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

     Frank Schaarschmidt and Daniel Gerhard by modifying the code of
     contrMat(multcomp)

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

     contrMat(multcomp)

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

     library(mratios)

     n=c(A=10,B=20,Z=10,D=10)

     contrMatRatio(n=n, type="Dunnett", base=1)
     contrMatRatio(n=n, type="Dunnett", base=3)

     contrMatRatio(n=n, type="Tukey")
     contrMatRatio(n=n, type="Sequen")
     contrMatRatio(n=n, type="AVE")
     contrMatRatio(n=n, type="GrandMean")
     contrMatRatio(n=n, type="Williams")
     contrMatRatio(n=n, type="UmbrellaWilliams")

