noether {rankFD}

Sample size calculation for the Wilcoxon-Mann-Whitney test using the Noether formula. The function estimates the sample size needed to detect the effect with pre-defined power at significance level alpha using Noether's formula'.

Description

Sample size calculation for the Wilcoxon-Mann-Whitney test using the Noether formula. The function estimates the sample size needed to detect the effect with pre-defined power at significance level alpha using Noether's formula'.

Usage

noether(alpha, power, t, p, x1 = c(0), ties = FALSE)

Arguments

alpha

two sided type I error rate

power

power: detect a relative effect p at least with probability power

t

proportion of subjects in the first group (between 0 and 1)

p

relative effect

x1

advance information is only needed in case of ties

ties

TRUE if ties are possible (non continuous distribution), otherwise FALSE

Value

Returns a data frame with the sample sizes for each group

References

Noether, G. E. (1987). Sample Size Determination for Some Common Nonparametric Tests. Journal of the American Statistical Association 85, 645.647.

Examples

noether(0.05,0.8,1/2, 0.75)