extract: extracts IRT item parameters

In lordif: Logistic Ordinal Regression Differential Item Functioning using IRT

Description

Extracts IRT item parameter estimates from an output returned from mirt

Usage

  extract(ipar)

Arguments

ipar	output from the mirt function of the mirt package

Details

similar to the coef function in the mirt package

Value

a data frame containing item parameter estimates in the order of a, cb1, cb2,..., cb(maxCat-1).

Author(s)

Seung W. Choi <[e-mail]>

See Also

lordif, mirt

Examples

##calib.sparse <- mirt(sparse.matrix,1,itemtype="gpcm") 
## Not run: ipar.sparse <- extract(calib.sparse)

Example output

Loading required package: mirt
Loading required package: stats4
Loading required package: lattice
Loading required package: rms
Loading required package: Hmisc
Loading required package: survival
Loading required package: Formula
Loading required package: ggplot2

Attaching package: 'Hmisc'

The following objects are masked from 'package:base':

    format.pval, round.POSIXt, trunc.POSIXt, units

Loading required package: SparseM

Attaching package: 'SparseM'

The following object is masked from 'package:base':

    backsolve

lordif documentation built on May 2, 2019, 2:13 p.m.