calc_posterior_single function

Calculate a posterior value of theta for a single item

Calculate a posterior value of theta for a single item.

calc_posterior_single(x, item_parm, resp, ncat, model, prior, prior_parm)

Arguments

• x: A length-one numeric vector for a theta value.
• item_parm: A numeric vector of item parameters (for one item).
• resp: A length-one numeric vector of item responses.
• ncat: A length-one numeric vector of the number of response categories by item.
• model: A length-one numeric vector of the IRT model by 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).