ExtractMirtPars {DFIT} | R Documentation |
Extracts the item parameters from a unidimensional mirt model
Description
Extracts the item parameters from a unidimensional mirt model
Usage
ExtractMirtPars(mod, focal = NULL, reference = NULL)
Arguments
mod |
A mirt object containing the fit of unidimensional model. |
focal |
Character. Required if mod is MultipleGroupClass, focal should coincide with the label for the focal group. If mod is SingleGroupClass, it is ignored. |
reference |
Character. Required if mod is MultipleGroupClass, reference should coincide with the label for the focal group. If mod is SingleGroupClass, it is ignored. |
Value
If mod contains any itemtype == "gpcm", a list with the item parameters and the estimate covariances (if available). If mod is SingleGroupClass, the list contains the item parameters as a matrix and the covariances as a list. If mod is MultipleGroupClass, the list contains the item parameters and covariances for the focal and reference groups only.
Examples
library(mirt)
(mod1 <- mirt(Science, model = 1, itemtype = c("graded", "graded", "gpcm", "gpcm"), SE = TRUE))
(ExtractMirtPars(mod1))