Extract an item object from mirt objects

Extract the internal mirt objects from any estimated model.

Usage

extract.item(x, item, group = NULL, drop.zeros = FALSE)

Arguments

x

mirt model of class 'SingleGroupClass', 'MultipleGroupClass', or 'MixtureClass'

item

a number or character signifying which item to extract

group

which group the item should be extracted from (applies to 'MultipleGroupClass' and 'MixtureClass' only). Can be a numeric value or the name of the group to be extracted

drop.zeros

logical; drop slope values that are numerically close to zero to reduce dimensionality? Useful in objects returned from bfactor or other confirmatory models that contain several zero slopes

References

Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. doi:10.18637/jss.v048.i06

See also

extract.group, extract.mirt

Examples

# \donttest{
mod <- mirt(Science, 1)
extr.1 <- extract.item(mod, 1)
# }