diffMeanVar (version 0.0.6)

LeveneTest: Test for equality of variance based on Levene test

Description

Test for equality of variance based on Levene test.

Usage

LeveneTest(value, group)

Arguments

value

numeric. Measurements to be compared between two groups.

group

numeric. Subject's group membership. Must be binary (i.e., taking values 0 or 1).

Value

A list with 2 elements:

stat

test statistic value

pval

pvalue of the score test

References

Levene H (1960) Robust tests for equality of variances. Contributions to probability and statistics: Essays in honor of Harold Hotelling, 2, 278-292.

Li X, Qiu W, Morrow J, DeMeo DL, Weiss ST, Fu Y, Wang X. (2015) A Comparative Study of Tests for Homogeneity of Variances with Application to DNA Methylation Data. PLoS ONE 10(12): e0145295. PMID: 26683022

Qiu W, Li X, Morrow J, DeMeo DL, Weiss ST, Wang X, Fu Y. New Score Tests for Equality of Variances in the Application of DNA Methylation Data Analysis [Version 2]. Insights Genet Genomics. (2017) 1: 3.2

Li X, Qiu W, Fu Y, Wang X. (2017) Robust Joint Score Tests in the Application of DNA Methylation Data Analysis. In submission.

Examples

# NOT RUN {
    # generate simulated data set from t distribution
    set.seed(1234567)
    es.sim = genSimData.tDistr(nCpGs = 100, nCases = 20, nControls = 20,
      df0 = 10, ncp0 = 0, df1 = 6, ncp1 = 2.393, testPara = "var",
      eps = 1.0e-3, applier = lapply) 
    print(es.sim)
    print(exprs(es.sim)[1:2,1:3])

    # do AW score test for the first probe
    dat = exprs(es.sim)
    pDat = pData(es.sim)
    print(pDat[1:2,])

    res = LeveneTest(value = dat[1,], group = pDat$memSubj)
    print(names(res))
    print(res)
# }