A data generation function along the lines of what was used in the Lai, Lavori, Liao paper. score rather than a normal distribution
generateNormalData(prevalence, N, mean, sd)
a three-column data frame of subGroup
, trt
(0 or 1), and score
a vector of group prevalences (length denoted by J below)
the sample size to generate
a 2 x J matrix of means under the null (first row) and alternative for each group
a 2 x J matrix of standard deviations under the null (first row) and alternative for each group