Generic S3 method for configuring the default prior for a bmmodel

Called by bmm() to automatically construct the priors for a given model, data and formula, and combine it with the prior given by the user. The first method executed is configure_prior.bmmodel, which will build the prior based on information from the model object such as fixed_parameters, default_priors, etc. Thus it is important to define these values in the model object. The function will also recognize if the user has specified that some parameters should be fixed to a constant and put the appropriate constant priors. Any additional priors that a developer wants to specify, which are not based on information in the model object, can be defined in the configure_prior.* method for the model, as mpt does; the example shows the form such a method takes.

Usage

configure_prior(model, data, formula, user_prior, ...)

Arguments

model

A bmmodel object

data

A data.frame containing the data used in the model

formula

A brmsformula object returned from configure_model()

user_prior

A brmsprior object given by the user as an argument to bmm()

...

Additional arguments passed to the method

Value

A brmsprior object containing the default priors for the model

Examples

if (FALSE) { # identical(Sys.getenv("BMM_EXAMPLES"), "true")
configure_prior.mymodel <- function(model, data, formula, user_prior, ...) {
  # a prior that depends on the data, which the model object cannot declare
  if (!"condition" %in% names(data)) {
    return(NULL)
  }
  brms::prior_("normal(0, 0.5)", class = "b", dpar = "kappa")
}
}