friedman_test: Friedman Rank Sum Test

In rstatix: Pipe-Friendly Framework for Basic Statistical Tests

Friedman Rank Sum Test

Description

Provides a pipe-friendly framework to perform a Friedman rank sum test, which is the non-parametric alternative to the one-way repeated measures ANOVA test. Wrapper around the function friedman.test().

See the Datanovia tutorial Friedman Test in R for a worked walkthrough.

Usage

friedman_test(data, formula, ...)

Arguments

data	a data.frame containing the variables in the formula.
formula	a formula of the form a ~ b | c, where a (numeric) is the dependent variable name; b is the within-subjects factor variables; and c (factor) is the column name containing individuals/subjects identifier. Should be unique per individual.
...	other arguments to be passed to the function friedman.test.

Value

return a data frame with the following columns:

• .y.: the y (dependent) variable used in the test.

• n: sample count.

• statistic: the value of Friedman's chi-squared statistic, used to compute the p-value.

• p: p-value.

• method: the statistical test used to compare groups.

See Also

The Datanovia tutorial: Friedman Test in R.

Examples

# Load data
#:::::::::::::::::::::::::::::::::::::::
data("ToothGrowth")
df <- ToothGrowth %>%
    filter(supp == "VC") %>%
    mutate(id = rep(1:10, 3))
head(df)

# Friedman rank sum test
#:::::::::::::::::::::::::::::::::::::::::
df %>% friedman_test(len ~ dose | id)

rstatix documentation built on July 24, 2026, 1:06 a.m.