`dataFrame.columns.stat — levene()`

Description

The levene() method of the stat object performs Levene's test for equality of variances across the selected columns.

Signature

dataFrame.columns(...columnNames).stat.levene({ sorted: false })

Scope: columns
Family: stat
Returns: object

Arguments

...columnNames ( string[] ): The name of the columns from which to compute Leven's test.
options (object): Levene test options.

Option

sorted (boolean)

Indicates whether the values are already sorted in ascending order.

Sorted: true
Not sorted: false (default)

Returns

stat (object)

A statistic object containing the Levene test results.

W_stat (number): The Levene test statistic.
p_value (number): The p-value associated with the test statistic.
confidence (number): A confidence score computed as 1 - p_value.
df_between (number): The between-groups degrees of freedom.
df_within (number): The within-groups degrees of freedom.

Notes

The method requires at least two selected columns.
The null hypothesis states that all groups have equal variances.
Small p-values indicate evidence against the assumption of equal variances.
The confidence score is calculated as 1 - p_value.
Levene's test is less sensitive to departures from normality than Bartlett's test.
The test is commonly used before performing ANOVA or other variance-based procedures.

Example

// compute the Levene test on values of multiple columns of the dataFrame
var stat = dataFrame.columns('groupA', 'groupB').stat.levene();

// log the stat details
notebook.log(stat);