theta_FB function

(C++) Calculate a theta estimate using FB (Full Bayes) method

theta_FB_single() and theta_FB() are functions for calculating a theta estimate using FB (Full Bayes) method.

theta_FB(
  nx,
  theta_init,
  theta_prop,
  items_list,
  item_init,
  resp,
  ncat,
  model,
  prior,
  prior_parm
)

theta_FB_single(
  nx,
  theta_init,
  theta_prop,
  item_mcmc,
  item_init,
  resp,
  ncat,
  model,
  prior,
  prior_parm
)

Arguments

• nx: the number of MCMC draws.

• theta_init: the initial estimate to use.

• theta_prop: the SD of the proposal distribution.

• item_init: item parameter estimates. Must be a vector for theta_FB_single(), and a matrix for theta_FB().

• resp: a vector containing responses on each item.

• ncat: a vector containing the number of response categories of each item.

• model: a vector indicating item models of each item, using

  • 1: 1PL model
  • 2: 2PL model
  • 3: 3PL model
  • 4: PC model
  • 5: GPC model
  • 6: GR model

• prior: an integer indicating the type of prior distribution, using

  • 1: normal distribution
  • 2: uniform distribution

• prior_parm: a vector containing parameters for the prior distribution.

• item_mcmc, items_list: sampled item parameters. Must be a matrix for theta_FB_single(), and a list of matrices for theta_FB().

Details

theta_FB_single() is designed for one item, and theta_FB() is designed for multiple items.

Currently supports unidimensional models.