calc_posterior_function function

Calculate a posterior distribution of theta

Calculate a posterior distribution of theta.

calc_posterior_function(
  theta_grid,
  item_parm,
  resp,
  ncat,
  model,
  prior,
  prior_parm
)

Arguments

• theta_grid: An equi-spaced grid of theta values.
• item_parm: A numeric matrix of item parameters.
• resp: a numeric vector containing item responses.
• ncat: A numeric vector of the number of response categories by item.
• model: A numeric vector indicating the IRT models of each item (1: 1PL, 2: 2PL, 3: 3PL, 4: PC, 5: GPC, 6: GR).
• prior: The type of prior distribution (1: normal, 2: uniform).
• prior_parm: A numeric vector of hyperparameters for the prior distribution, c(mu, sigma) or c(ll, ul).