bf_test Calculates the Brown-Forsythe test for homogeneity
of variance across groups, coefficients, variance-covariance matrix,
and degrees of freedom.
Usage
bf_test(y, x, formula, data)
Value
An object containing:
fstats F-test value, including numerator and
denominator degrees of freedom.
qhat pooled coefficients from fit.
vcov variance-covariance matrix.
dfcom degrees of freedom obtained from df.residual.
Arguments
y
numeric response variable.
x
categorical variable.
formula
A formula object to specify the model as normally
used by glm. Use 'factor' to define the grouping variable.
data
An objects of class milist, created by
df2milist, list2milist or mids2milist.
Author
Martijn Heymans, 2021
Details
The Levene's test centers around means to calculate
outcome residuals, the Brown-Forsythe test around the median.