get_covbeta: Compute cov(beta) as a function of varpar of an LMM
Description
At the optimum cov(beta) is available as vcov(lmer-model). This function
computes cov(beta) at non (RE)ML estimates of varpar
.
Usage
get_covbeta(varpar, devfun)
Value
cov(beta) at supplied varpar values.
Arguments
- varpar
variance parameters; varpar = c(theta, sigma)
.
- devfun
deviance function as a function of theta only.
Author
Rune Haubo B. Christensen. Adapted to pbkrtest by Søren Højsgaard.