Skip to contents

Tukey's HSD post hoc test is a modified t-test applied for all features to all pairs of levels in a factor. It is used to determine which groups are different (if any). A multiple test corrected p-value is computed to indicate which groups are significantly different to the others for each feature.

Usage

HSD(alpha = 0.05, mtc = "fdr", formula, unbalanced = FALSE, ...)

Arguments

alpha

(numeric) The p-value cutoff for determining significance. The default is 0.05.

mtc

(character) Multiple test correction method. Allowed values are limited to the following:

  • "bonferroni": Bonferroni correction in which the p-values are multiplied by the number of comparisons.

  • "fdr": Benjamini and Hochberg False Discovery Rate correction.

  • "none": No correction.

The default is "fdr".

formula

(formula) A symbolic description of the model to be fitted.

unbalanced

(logical) Unbalanced model. Allowed values are limited to the following:

  • "TRUE": A correction is applied for unbalanced designs.

  • "FALSE": No correction is applied for unbalanced designs.

The default is FALSE.

...

Additional slots and values passed to struct_class.

Value

A HSD object with the following output slots:

difference(data.frame)
UCL(data.frame)
LCL(data.frame)
p_value(data.frame) The probability of observing the calculated statistic if the null hypothesis is true.
significant(data.frame) True/False indicating whether the p-value computed for each variable is less than the threshold.

Details

This object makes use of functionality from the following packages:

  • agricolae

Inheritance

A HSD object inherits the following struct classes:

[HSD] >> [model] >> [struct_class]

References

de Mendiburu F (2023). agricolae: Statistical Procedures for Agricultural Research. R package version 1.3-7, https://CRAN.R-project.org/package=agricolae.

Examples

M = HSD(
      alpha = 0.05,
      mtc = "fdr",
      formula = y ~ x,
      unbalanced = FALSE)

D = iris_DatasetExperiment()
M = HSD(formula=y~Species)
M = model_apply(M,D)