samplesize: Calculates approximate sample size for two-stage...
In kolassa-dev/twostage: Two Stage MWW

Calculates approximate sample size for two-stage Mann-Whitney-Wilcoxon statistic.

samplesize(
  omega,
  lambda11 = 0.25,
  lambda12 = 0.25,
  lambda21 = 0.25,
  lambda22 = 0.25,
  alpha2 = 0.05,
  beta = 0.2,
  round = TRUE
)

`omega`	Alternative P(Y>X)-.5
`lambda11`	Proportion in group 1, first evaluation
`lambda12`	Proportion in group 1, second evaluation
`lambda21`	Proportion in group 2, first evaluation
`lambda22`	Proportion in group 2, second evaluation
`alpha2`	Overall test size
`beta`	Type II error rate.
`round`	Logical Should sample size be rounded?