power.twosampt {FDRsampsize}

Compute power of the two-samples t-test

Description

Estimate power of the two-samples t-test;Uses classical power formula for two-sample t-test;Assumes equal variance and sample size

Usage

power.twosampt (n, alpha, delta, sigma = 1) 

Arguments

n

per-group sample size (scalar)

alpha

p-value threshold (scalar)

delta

difference between population means (vector)

sigma

standard deviation (vector or scalar)

Details

For many applications, the null.effect is zero difference of means.

Value

vector of power estimates for two-sided test

Examples

 power.twosampt        # show the power function
 res=fdr.sampsize(fdr=0.1,
                  ave.pow=0.8,
                  pow.func=power.twosampt,
                  eff.size=rep(c(2,0),c(100,900)),
                  null.effect=0,
                  sigma=1)
 res