homogtestTwoWay: Variance Homogeneity Tests for Two-Way Layout

In twowaytests: Two-Way Tests in Independent Groups Designs

Variance Homogeneity Tests for Two-Way Layout

Description

homogtestTwoWay performs variance homogeneity tests including Levene, Bartlett, Fligner-Killeen tests for two-way layout.

Usage

homogtestTwoWay(formula, data, method = c("Levene", "Bartlett", "Fligner"), 
  alpha = 0.05, na.rm = TRUE, verbose = TRUE)

Arguments

formula	a formula of the form lhs ~ rhs where lhs gives the sample values and rhs the corresponding two factors.
data	a data frame containing the variables in formula
method	a character string to select one of the variance homogeneity tests. "Levene": Levene's test, "Bartlett": Bartlett's test, "Fligner": Fligner-Killeen test.
alpha	the level of significance to assess variance homogenity. Default is set to alpha = 0.05.
na.rm	a logical value indicating whether NA values should be stripped before the computation proceeds.
verbose	a logical for printing output to R console.

Value

A list containing the following components:

statistic	the corresponding test statistic.
parameter	the parameter(s) of the approximate corresponding distribution of the test statistic. The corresponding distribution is F distribution for Levene's test, Chi-square disribution for Bartlett's test and Fligner-Killeen test.
p.value	the p-value of the test.

Author(s)

Osman Dag, Malwane Ananda, Sam Weerahandi

See Also

leveneTest bartlett.test fligner.test

Examples

library(twowaytests)
data(alveolar)

homogtestTwoWay(cell ~ ovalbumin*treatment, data = alveolar)
homogtestTwoWay(cell ~ ovalbumin*treatment, data = alveolar, method = "Bartlett")

twowaytests documentation built on March 31, 2023, 9:26 p.m.