extract.group: Extract a group from a multiple group mirt object

In philchalmers/mirt: Multidimensional Item Response Theory

Extract a group from a multiple group mirt object

Description

Extract a single group from an object defined by multipleGroup, or as a mixture model from mirt.

Usage

extract.group(x, group)

Arguments

x	model object of class 'MultipleGroupClass' or 'MixtureClass'
group	the name of the group to extract

Author(s)

Phil Chalmers [e-mail]

References

Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.18637/jss.v048.i06")}

See Also

extract.item, extract.mirt

Examples

set.seed(12345)
a <- matrix(abs(rnorm(15,1,.3)), ncol=1)
d <- matrix(rnorm(15,0,.7),ncol=1)
itemtype <- rep('2PL', nrow(a))
N <- 1000
dataset1 <- simdata(a, d, N, itemtype)
dataset2 <- simdata(a, d, N, itemtype, mu = .1, sigma = matrix(1.5))
dat <- rbind(dataset1, dataset2)
group <- c(rep('D1', N), rep('D2', N))
models <- 'F1 = 1-15'

mod_configural <- multipleGroup(dat, models, group = group)
group.1 <- extract.group(mod_configural, 'D1') #extract first group
summary(group.1)
plot(group.1)

philchalmers/mirt documentation built on March 29, 2025, 10:42 a.m.