TreeLRT: Likelihood Ratio Test for Tree Ordered Alternatives

In TreeOrderTests: Tests for Tree Ordered Alternatives in One-Way ANOVA

Likelihood Ratio Test for Tree Ordered Alternatives

Description

Performs a likelihood ratio test for testing the equality of means against tree ordered alternatives.

Usage

TreeLRT(sample_data, significance_level, n.boot = 1e+05, seed = NULL)

Arguments

sample_data	A list of numeric vectors. The first element represents the control group, the others represent treatment groups.
significance_level	A numeric value between 0 and 1 specifying the significance level for the test (e.g., 0.05).
n.boot	Number of bootstrap replications to estimate the critical value (default is 100000).
seed	Optional random seed for reproducibility.

Details

This test compares the null hypothesis of equal means for all groups to the alternative that the control group mean is less than or equal to the treatment group means under the tree order restriction.

The likelihood ratio statistic is computed using constrained maximum likelihood estimates under the null and tree ordered alternative hypotheses. The critical value is estimated by a bootstrap procedure.

Value

A character string with the critical value, the LRT test statistic, and the test decision.

Author(s)

Subha Halder

See Also

Halder, Mondal, and Kumar (2025) "Testing Against Tree Ordered Alternatives in One-way ANOVA" <https://arxiv.org/abs/2507.17229>

Examples

# Generate data
set.seed(456)
control <- rnorm(10, mean = 5)
treatment1 <- rnorm(10, mean = 6)
treatment2 <- rnorm(10, mean = 7)

sample_data <- list(control, treatment1, treatment2)

# Run LRT at 5% significance level
TreeLRT(sample_data, 0.05, n.boot = 1000)


TreeLRT(sample_data, 0.05, n.boot = 100000)

TreeOrderTests documentation built on Aug. 8, 2025, 6:40 p.m.