R: Change polytomous items to dichotomous item format

poly2dich {mirt}

R Documentation

Change polytomous items to dichotomous item format

Description

Tranforms a matrix of items into a new matrix where the select polytomous items have been converted into comperable dichotomous items with the same information.

Usage

poly2dich(data, which.items = 1:ncol(data))

Arguments

`data`	an object of class `data.frame` or `matrix`
`which.items`	a vector indicating which items should be transformed into the dichotomous form. Default uses all input items

Value

Returns an integer matrix

Author(s)

Phil Chalmers rphilip.chalmers@gmail.com

Examples


## Not run: 
data(Science)

head(Science)
newScience <- poly2dich(Science)
head(newScience)

newScience2 <- poly2dich(Science, which.items = 2)
head(newScience2)


## End(Not run)

[Package mirt version 1.21 Index]