Extract the trace of the `hat' matrix
Extract the trace of the `hat' matrix from a fitted linear mixed model or generalized linear mixed model.
- a fitted model object that inherits from the
- The trace of the hat matrix at the parameter estimates. This is a measure of the complexity of the model, conditional on the relative variance components.
Spiegelhalter, D.J., Best, N.G., Carlin, B.P. and van der Linde, A. (2002), "Bayesian measures of model complexity and fit (with discussion)", Journal of the Royal Statistical Society, part B, 64, (4), 583-639.
hatTrace(lmer(Reaction ~ Days + (1|Subject) + (0+Days|Subject), sleepstudy))