poly2dich {mirt} | R Documentation |
Transforms a matrix of items into a new matrix where the select polytomous items have been converted into comparable dichotomous items with the same information.
poly2dich(data, which.items = 1:ncol(data), sep = "_cat.")
data |
an object of class |
which.items |
a vector indicating which items should be transformed into the dichotomous form. Default uses all input items |
sep |
character vector pattern to append to each item name in |
Returns an integer matrix
Phil Chalmers rphilip.chalmers@gmail.com
Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. doi: 10.18637/jss.v048.i06
## Not run: data(Science) head(Science) newScience <- poly2dich(Science) head(newScience) newScience2 <- poly2dich(Science, which.items = 2) head(newScience2) ## End(Not run)