contrMatRatio {mratios} | R Documentation |
Creates numerator and denominator contrast matrices for some common multiple comparison and trend test problems, for internal use in the sci.ratio and simtest.ratio functions. A suggestion how to define contrast matrices for ratios analogously for most of the problems covered by the contrMat-function in the multcomp-package for differences of means.
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.
contrMatRatio(n, type = "Tukey", base = 1)
n |
integer vector of sample sizes |
type |
the type of multiple contrasts
|
base |
a single integer specifying the control (i.e. denominator) group for "Dunnett" contrasts |
This is a simple adaption of the contrMat function in the package multcomp for ratio hypotheses.
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.
Frank Schaarschmidt, by slightly modifying the code of contrMat(multcomp)
contrMat(multcomp)
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="Williams")