What is the influence function used for binary classification in the R package partkit, specifically for the conditional tree (ctree). I could not find any details in the R package documentation. In the vigente I found this paragraph about classification:

enter image description here

But the function $e_J(Y_i)$ is not defined. What is $e_J(Y_i)$? and is it the influence function used for the function ctree?


1 Answer 1


The function is defined at the top of page 10 in vignette("ctree", package = "partykit"), albeit briefly: $e_K(k)$ is the unit vector of length $K$ with $k$-th element being equal to one.

As an example, if you do classification with $J = 4$ classes and the second class is observed in observation $i$ with $Y_i = 2$, then $e_J(Y_i) = (0, 1, 0, 0)^\top$.

See also the following for more explanations: What is the test statistics used for a conditional inference regression tree?


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.