rpcm: Simulate Data under a Partial Credit Model

In psychotools: Psychometric Modeling Infrastructure

Simulate Data under a Partial Credit Model

Description

rpcm simulates IRT data under a partial credit model.

Usage

rpcm(theta, delta, nullcats = FALSE, return_setting = TRUE)

Arguments

theta	numeric vector of person parameters. Can also be a list, then a list of length length(theta) is returned, containing multiple simulated data sets.
delta	list of numeric vectors of item threshold parameters.
nullcats	logical. Should null categories be allowed?
return_setting	logical. Should a list containing slots of "delta", and "theta", as well as the simulated data matrix "data" be returned (default) or only the simulated data matrix?

Value

rpcm returns either a list of the following components:

delta	list of numeric vectors of item threshold parameters used,
theta	numeric vector of person parameters used,
data	numeric matrix containing the simulated data,

or (if return_setting = FALSE) only the numeric matrix containing the simulated data.

See Also

rgpcm, rrsm, rrm, rpl

Examples

set.seed(1)
## item responses under a partial credit model (PCM) with
## 6 persons with three different person parameters
## 8 items with different combinations of two or three threshold parameters
ppar <- rep(-1:1, each = 2)
tpar <- rep(list(-2:0, -1:1, 0:1, 0:2), each = 2)
sim <- rpcm(theta = ppar, delta = tpar)

## simulated item response data along with setting parameters
sim

## print and plot corresponding item response object
iresp <- itemresp(sim$data)
iresp
plot(iresp)

psychotools documentation built on May 29, 2024, 8:12 a.m.