Levene's Test — levene_test • rstatix

Provide a pipe-friendly framework to easily compute Levene's test for homogeneity of variance across groups.

Wrapper around the function leveneTest(), which can additionally handles a grouped data.

levene_test(data, formula, center = median)

Arguments

data: a data frame for evaluating the formula or a model
formula: a formula
center: The name of a function to compute the center of each group; mean gives the original Levene's test; the default, median, provides a more robust test.

Value

a data frame with the following columns: df1, df2 (df.residual), statistic and p.

Examples

# Prepare the data
data("ToothGrowth")
df <- ToothGrowth
df$dose <- as.factor(df$dose)
# Compute Levene's Test
df %>% levene_test(len ~ dose)
#> # A tibble: 1 × 4
#>     df1   df2 statistic     p
#>   <int> <int>     <dbl> <dbl>
#> 1     2    57     0.646 0.528

# Grouped data
df %>%
  group_by(supp) %>%
  levene_test(len ~ dose)
#> # A tibble: 2 × 5
#>   supp    df1   df2 statistic     p
#>   <fct> <int> <int>     <dbl> <dbl>
#> 1 OJ        2    27      1.84 0.178
#> 2 VC        2    27      2.17 0.134