Compute power of rank-sum test; Uses formula of Noether (JASA 1987), which is based on asymptotic normal approximation.
Usage
power.ranksum(n, alpha, p)
Value
Vector of power estimates for two-sided tests
Arguments
n
sample size (scalar)
alpha
p-value threshold (scalar)
p
Pr(Y>X), as in Noether (JASA 1987)
Details
In most applications, the null effect size will be designated by p = 0.5
References
Noether, Gottfried E (1987) Sample size determination for some common nonparametric tests. Journal of the American Statistical Association, 82:645-647.