computeResponseProbability function

(internal) compute response probability

computeResponseProbability is an internal function for computing response probability from a set of item parameters.

computeResponseProbability(ipar, model, theta_grid)

Arguments

• ipar: a data.frame containing item parameters.
• model: the item model to use. Accepts grm or gpcm.
• theta_grid: theta values to compute probability values at.

Returns

computeResponseProbability returns an item-wise list of probability matrices.

Examples

ipar <- PROsetta:::extractAnchorParameters(data_asq, FALSE)
theta_q <- seq(-4, 4, .1)
p <- PROsetta:::computeResponseProbability(ipar, "grm", theta_q)

plot(
  0, 0, type = "n", xlim = c(-4, 4), ylim = c(0, 1),
  xlab = "Theta", ylab = "Response probability"
)
lines(theta_q, p[[1]][, 1])
lines(theta_q, p[[1]][, 2])
lines(theta_q, p[[1]][, 3])
lines(theta_q, p[[1]][, 4])
lines(theta_q, p[[1]][, 5])