R/bridge_sampler_tools.R

In bridgesampling: Bridge Sampling for Marginal Likelihoods and Bayes Factors

#--------------------------------------------------------------------------
# functions for Stan support via rstan
#--------------------------------------------------------------------------

# taken from rstan:
.rstan_relist <- function (x, skeleton) {
  lst <- utils::relist(x, skeleton)
  for (i in seq_along(skeleton)) dim(lst[[i]]) <- dim(skeleton[[i]])
  lst
}

# taken from rstan:
.create_skeleton <- function (pars, dims) {
  lst <- lapply(seq_along(pars), function(i) {
    len_dims <- length(dims[[i]])
    if (len_dims < 1)
      return(0)
    return(array(0, dim = dims[[i]]))
  })
  names(lst) <- pars
  lst
}

.stan_log_posterior <- function(s.row, data) {
  out <- tryCatch(rstan::log_prob(object = data$stanfit, upars = s.row), error = function(e) -Inf)
  if (is.na(out)) out <- -Inf
  return(out)
}