log_normal_variance_one_way: Test the equality of variance parameters of log normal...

In LRTesteR: Likelihood Ratio Tests and Confidence Intervals

Test the equality of variance parameters of log normal distributions.

Description

Test the equality of variance parameters of log normal distributions.

Usage

log_normal_variance_one_way(x, fctr, conf.level = 0.95)

Arguments

x	a numeric vector of data.
fctr	a factor vector indicating groups.
conf.level	overall confidence level of the likelihood intervals. Uses Bonferroni correction.

Details

• Null: All variances are equal. (o^2_1 = o^2_2 ... o^2_k).

• Alternative: At least one variance is not equal.

Value

An S3 class containing the test statistic, p value, list of likelihood based confidence intervals, overall confidence level, individual confidence level of each interval and alternative hypothesis.

Source

• https://en.wikipedia.org/wiki/Likelihood-ratio_test

• Yudi Pawitan. In All Likelihood. Oxford University Press.

• Hodd, McKean, and Craig. Introduction to Mathematical Statistics. Pearson.

Examples

library(LRTesteR)

# Null is true
set.seed(1)
x <- rlnorm(150, 1, 1)
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
log_normal_variance_one_way(x, fctr, .95)

# Null is false
set.seed(1)
x <- c(rlnorm(50, 1, 1), rlnorm(50, 1, 2), rlnorm(50, 1, 3))
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
log_normal_variance_one_way(x, fctr, .95)

LRTesteR documentation built on June 8, 2025, 12:06 p.m.