ifr_levene_test: Levene's test for equality of variances

In inferr: Inferential Statistics

Levene's test for equality of variances

Description

ifr_levene_test reports Levene's robust test statistic for the equality of variances and the two statistics proposed by Brown and Forsythe that replace the mean in Levene's formula with alternative location estimators. The first alternative replaces the mean with the median. The second alternative replaces the mean with the 10

Usage

ifr_levene_test(data, ...)

## Default S3 method:
ifr_levene_test(data, ..., group_var = NULL, trim_mean = 0.1)

Arguments

data	a data.frame or tibble
...	numeric; columns in data
group_var	factor; column in data
trim_mean	trimmed mean

Value

ifr_levene_test returns an object of class "ifr_levene_test". An object of class "ifr_levene_test" is a list containing the following components:

bf	Brown and Forsythe f statistic
p_bf	p-value for Brown and Forsythe f statistic
lev	Levene's f statistic
p_lev	p-value for Levene's f statistic
bft	Brown and Forsythe f statistic using trimmed mean
p_bft	p-value for Brown and Forsythe f statistic using trimmed mean
avgs	mean for each level of the grouping variable
sds	standard deviations for each level of the grouping variable
avg	combined mean
sd	combined standard deviation
n	number of observations
n_df	numerator degrees of freedom
d_df	denominator degrees of freedom
levs	levels of the grouping variable
lens	number of observations for each level of the grouping variable
type	alternative hypothesis

Deprecated Function

infer_levene_test() has been deprecated. Instead use ifr_levene_test().

References

Bland, M. 2000. An Introduction to Medical Statistics. 3rd ed. Oxford: Oxford University Press.

Brown, M. B., and A. B. Forsythe. 1974. Robust tests for the equality of variances. Journal of the American Statistical Association 69: 364–367.

Carroll, R. J., and H. Schneider. 1985. A note on Levene’s tests for equality of variances. Statistics and Probability Letters 3: 191–194.

Examples

# using grouping variable
ifr_levene_test(hsb, read, group_var = race)

# using  variables
ifr_levene_test(hsb, read, write, socst)

inferr documentation built on April 4, 2025, 2:08 a.m.