lordif (version 0.1-2)

extract: extracts item parameters

Description

extracts IRT item parameter estimates from an output returned from ltm:grm

Usage

extract(ipar)

Arguments

ipar

output from the grm function in the ltm package

Value

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

Details

similar to the coef function in the ltm package

See Also

lordif

Examples

##calib.sparse <- grm(sparse.matrix,constrained=FALSE,IRT.param=TRUE) 
ipar.sparse <- extract(calib.sparse)