levene_test function

Calculates the Levene's test

levene_test Calculates the Levene's test for homogeneity of variance across groups, model coefficients, the variance-covariance matrix and the degrees of freedom.

levene_test(y, x, formula, data)

Arguments

• y: numeric (continuous) response variable.
• x: categorical group variable.
• formula: A formula object to specify the model as normally used by glm. Use 'factor' to define the grouping x variable. Only one variable is allowed.
• data: An objects of class milist, created by df2milist, list2milist or mids2milist.

Returns

An object from which the following objects are extracted:

• fstats F-test value, including numerator and denominator degrees of freedom.
• qhat model coefficients.
• vcov variance-covariance matrix.
• dfcom degrees of freedom obtained from df.residual.

Details

The Levene's test centers on group means to calculate outcome residuals, the Brown-Forsythe test on the median.

Examples

imp_dat <- df2milist(lbpmilr, impvar="Impnr")
ra <- with(imp_dat, expr=levene_test(Pain ~ factor(Carrying)))

See Also

with.milist, pool_levenetest, bf_test

Author(s)

Martijn Heymans, 2021