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Shifted Gamma Model for brms

Source: R/rt_gamma_brms.R
rt_gamma.Rd

Provides the necessary functions to use a shifted Gamma distribution as a custom family in brms. This version is parameterized using tau (proportion of non-decision time relative to minimum RT) and minrt (minimum possible RT), where the non-decision time ndt = tau * minrt. The distribution is parameterized by the shape (mu in brms, alpha in standard Gamma) and scale (sigma in brms, beta in standard Gamma), as well as tau, and minrt (which is typically fixed).

Usage

rt_gamma(
  link_mu = "softplus",
  link_sigma = "softplus",
  link_tau = "logit",
  link_minrt = "identity"
)

rt_gamma_lpdf_expose()

rt_gamma_stanvars()

log_lik_rt_gamma(i, prep)

posterior_predict_rt_gamma(i, prep, ...)

posterior_epred_rt_gamma(prep)

Arguments

Link functions for the parameters.

i, prep

For brms' functions to run: index of the observation and a brms preparation object.

...

Additional arguments.

Value

A brms::custom_family object.