I don't remember. I think that I had to estimate a Q-Matrix for a Cognitive Diagnostic Model. I probably hooked on a one, very specific algorithm, and because I was unable to find it's implementation in R I created my own. But the problem is, that there are better algorithms implemented in existing R packages. Here are some references (I wish I had used one of them):
Every cloud has a silver lining. Now I have here some resources if I ever needed to go back to the subject.
You can install cdmQMatrix from github with:
# install.packages("devtools")
devtools::install_github("zzawadz/cdmQMatrix")
## basic example
library(ltm)
library(cdmQMatrix)
data("WIRS")
fitQmat(WIRS, verbose = TRUE)$final.mat
# Item 1 Item 2 Item 3 Item 4 Item 5 Item 6
# Item1 1 0 1 0 1 1
# Item2 0 0 0 1 0 1
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