dof_KR: compute denominator degrees-of-freedom approximations

In glmmTMB: Generalized Linear Mixed Models using Template Model Builder

compute denominator degrees-of-freedom approximations

Description

dof_KR uses an adaptation of the machinery from the pbkrtest package to compute the Kenward-Roger approximation of the 'denominator degrees of freedom' for each fixed-effect coefficient in the conditional model; dof_satt does the same for Satterthwaite approximations

Usage

dof_KR(model)

dof_satt(model, L = diag(length(fixef(model)$cond)))

Arguments

model	a fitted glmmTMB object
L	a contrast matrix: by default, equal to an identity matrix (i.e., ddfs are returned for each fixed-effect parameter)

Details

Kenward-Roger adjustments should not be used for models fitted with ML rather than REML; the theory is only well understood, and the model is only tested, for LMMs (family = "gaussian"). Use at your own risk for GLMMs!

Value

a named vector of ddf for each conditional fixed-effect parameter; dof_KR includes attributes 'vcov' (Kenward-Roger adjusted covariance matrix) and 'se' (the corresponding standard errors)

glmmTMB documentation built on Jan. 15, 2026, 9:07 a.m.