CDM: item_by_group – R documentation

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CDM

item_by_group

Create Dataset with Group-Specific Items

Description

Creates a dataset with group-specific items which can be used for multiple group comparisons.

Usage

item_by_group(dat, group, invariant=NULL, rm.empty=TRUE)

Arguments

`dat`	Dataset with item responses
`group`	Vector of group identifiers
`invariant`	Optional vector of variables which should not be made group-specific, i.e. which should be treated as invariant across groups.
`rm.empty`	Logical indicating whether empty columns should be removed

Value

Extended dataset with item responses

Examples

## Not run: 
#############################################################################
# EXAMPLE 1: Create dataset with group-specific item responses
#############################################################################

data(data.mg, package="CDM")
dat <- data.mg

#-- create dataset with group-specific item responses
dat0 <- CDM::item_by_group( dat=dat[,paste0("I",1:5)], group=dat$group )

#-- summary statistics
summary(dat0)
colnames(dat0)

#-- set some items to invariant
invariant_items <- c("I1","I4")
dat1 <- CDM::item_by_group( dat=dat[,paste0("I",1:5)], group=dat$group,
            invariant=invariant_items)
colnames(dat1)

## End(Not run)

CDM

Cognitive Diagnosis Modeling

v7.5-15

GPL (>= 2)

Authors

Alexander Robitzsch [aut, cre], Thomas Kiefer [aut], Ann Cathrice George [aut], Ali Uenlue [aut]

Initial release

2020-03-10 14:19:21