power.fdr.tt: Power and sample size for False Discovery Rate (FDR) with...

In statapps/power.ctepd: Power and sample size for clinical trials and epidemiology

Power and sample size for False Discovery Rate (FDR) with t-tests

Description

Compute power and sample size of test or determine the effect size under alternative hypothesis to obtain target power for false discovery rate(same as power.anova.test).

Usage

  power.fdr.tt(n1=NULL, cc.ratio=1, pi0=0.99, fdr=0.05, delta=NULL, 
              power = NULL, sigma=1, tol = .Machine$double.eps^0.25)

Arguments

n1	Number of cases
cc.ratio	Control / case ratio, default is 1
fdr	False Discovery Rate (FDR)
power	Power of test (1 minus Type II error probability)
pi0	Percentage of null, default is 0.99
delta	Difference under althernative hypothesis
sigma	Variance of distribution
tol	tol for uniroot function

Details

Calculate power and sample size of study that requires control of False Discovery Rate (for example, analysis of RNA Micro-Array data. The algorithm is based on methods proposed by Liu and Hwang (2007).

Exactly one of the parameters 'n1','power' and 'delta' must be passed as NULL, and that parameter is determined from the others. Notice that the last one has non-NULL default so NULL must be explicitly passed if you want to compute it.

Value

Object of class 'power.htest', a list of the arguments (including the computed one) augmented with 'method' and 'note' elements.

case.control	A vector for number of cases and controls
n.total	Total number of sample size for the study
pi0	Percentage of null distributions
sigma	Varaince of the distribution
fdr	False Discovery Rate
Power	Power of the test
delta	Difference of means under althernative hypothesis
c.reject	Critical value to reject the null hypothesis

Note

'uniroot' is used to solve power equation for unknowns, so you may see errors from it, notably about inability to bracket the root when invalid arguments are given.

Author(s)

Bingshu E. Chen ([e-mail])

References

Liu, P. and Hwang J T.(2007). Quick calculation for sample size while controlling false discovery rate with application to microarray analysis. Bioinformatics, 23, 739-746.

See Also

power.pga.snp, power.surv.test, power.t.test, pwr.2p.test

Examples

# Example from the paper.
power.fdr.tt(n1 = 45, delta = 0.3, pi0 = 0.9, sigma = 0.5, fdr = 0.1)

statapps/power.ctepd documentation built on April 26, 2024, 3:22 a.m.