methodRuleWMW: Function to pick the method for wmwTest given the data and exact argument.
Description
Inputs x,y,exact, and chooseLimit, and outputs the method, one of 'asymptotic', 'exact.ce', or 'exact.mc'
Usage
methodRuleWMW(x, y, exact, chooseLimit = 5000)
Value
a character vector with one element, either:
asymptotic
for using normal approximations
exact.ce
for using exact methods with complete enumeration
exact.mc
for a Monte Carlo implementation of the exact version of the test
Arguments
x
vector of numeric responses from group 1
y
vector of numeric responses from group 2
exact
logical, should exact methods be used?
chooseLimit
boundary for choosing between methods
Details
Let J=choose(m+n,n) where length(x)=m and length(y)=n. If exact=NULL then return 'exact.ce' if J is less than or equal to chooseLimit, otherwise return 'asymptotic'. If exact=FALSE return 'asymptotic'. If exact=TRUE then
return 'exact.ce' if J is less than or equal to chooseLimit, otherwise return 'exact.mc'.