psychotools (version 0.7-4)

rrm: Simulate Data under a Rasch model

Description

rrm simulates IRT data under a Rasch model.

Usage

rrm(theta, beta, return_setting = TRUE)

Value

rrm returns either a list of the following components:

beta

numeric vector of item difficulty 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.

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 matrices.

beta

numeric vector of item difficulty parameters.

return_setting

logical. Should a list containing slots of "beta", and "theta", as well as the simulated data matrix "data" be returned (default) or only the simulated data matrix.

See Also

rpl, rpcm, rrsm, rgpcm

Examples

set.seed(1)
## item responses under a Rasch model from
## 6 persons with three different person parameters
## 9 increasingly difficult items
ppar <- rep(-1:1, each = 2)
ipar <- seq(-2, 2, by = 0.5)
sim <- rrm(theta = ppar, beta = ipar)

## simulated item response data along with setting parameters
sim

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