CDM (version 2.7-7)

coef: Extract Estimated Item Parameters

Description

Extracts the estimated parameters from either din, gdina or gdm objects.

Usage

## S3 method for class 'din':
coef(object, \dots)

## S3 method for class 'gdina':
coef(object, \dots)

## S3 method for class 'gdm':
coef(object, \dots)

Arguments

object

An object inheriting from either class din, class gdina or class gdm.

...

Additional arguments to be passed.

Value

• A matrix or a data frame of the estimated parameters for the fitted model.

See Also

din, gdina, gdm

Examples

# use sim.dina dataset
data(sim.dina)

# DINA model
d1 <- din(sim.dina, q.matr = sim.qmatrix)
coef(d1)

# GDINA model
d2 <- gdina(sim.dina, q.matr = sim.qmatrix)
coef(d2)

# GDM model (use only 10 iterations for computation time reasons)
theta.k <- seq(-4,4,len=11)
d3 <- gdm( sim.dina , irtmodel="2PL" , theta.k=theta.k , 
     Qmatrix=as.matrix(sim.qmatrix) , centered.latent=TRUE , maxiter=10 )
coef(d3)