Create a function to calculate the meta model log likelihood
Source:R/meta_gen.R
epidist_gen_meta_log_lik.RdIndividual level rows use the marginal model log likelihood created by
epidist_gen_log_lik(). Summary rows use the sampling distributions
described in as_epidist_meta_model(), evaluated at the implied summaries
for each posterior draw. A row that stands for several summaries reported by
one study returns the joint log likelihood of all of them, so an observation
here is a group of summaries rather than a single reported value.
Arguments
- family
A description of the response distribution and link function to be used in the model. Every family function has a link argument allowing users to specify the link function to be applied on the response variable. If not specified, default links are used. For details of all supported families see
brms::brmsfamily(). Commonly used, such asbrms::lognormal(), are also reexported as part ofepidist.
Value
A function that calculates the log likelihood for a single
observation. The prep object must have the meta model vint and vreal
slots.
Details
Summary rows are evaluated in R, one posterior draw at a time, and each
evaluation can run a quadrature of up to 2000 intervals by default. The
cost of brms::log_lik() and loo::loo() therefore grows with the number
of draws times the number of summary rows. Pass ndraws to either to use
fewer draws, at the price of noisier estimates.
See also
brms::log_lik() for details on the brms log likelihood interface.
Other gen:
epidist_gen_log_lik(),
epidist_gen_meta_predict(),
epidist_gen_posterior_epred(),
epidist_gen_posterior_predict()