tulpa_family: Construct a minimal tulpa_family for simulation

In tulpa: Templated Unified Library for Posterior Approximation in Bayesian Hierarchical Models

Construct a minimal tulpa_family for simulation

Description

Lightweight constructor for a tulpa_family object that exposes the contract required by prior_predict() and tulpa_simulate(). Model packages (tulpaRatio, tulpaObs) register richer families that also link to C++ likelihoods; this helper is for tests and simple custom families that only need simulation.

Usage

tulpa_family(
  name,
  simulate_fn,
  process_names = "y",
  extra_params = list(),
  link_inv = NULL
)

## S3 method for class 'tulpa_family'
print(x, ...)

Arguments

name	Family name (character, length 1).
simulate_fn	⁠function(eta, params, n_obs, ...)⁠ returning a numeric vector of length n_obs (single-process) or a list of such vectors keyed by process_names (multi-process). eta is a list of linear predictors, one per process.
process_names	Character vector. Defaults to "y" (single-process).
extra_params	Named list of tulpa_prior objects for likelihood- specific scalar parameters (e.g., dispersion phi). Drawn at each prior-predictive iteration. Defaults to empty.
link_inv	List of inverse-link functions per process; defaults to identity for every process. tulpa passes the raw linear predictor to simulate_fn, so most families implement the link inside simulate_fn (e.g., mu = exp(eta) for Poisson). The link_inv slot exists for families that prefer to keep the inverse-link separate.
x	A tulpa_family.
...	Ignored.

Value

A tulpa_family object.

Examples

fam <- tulpa_family(
  name = "poisson",
  simulate_fn = function(eta, params, n_obs, ...) {
    rpois(n_obs, exp(eta[[1]]))
  }
)

tulpa documentation built on Oct. 19, 2026, 5:09 p.m.