The author has since edited the question so that it has almost nothing in common with the original, except that both involve machine learning in R. The new question, about a specific error in the
deal package, is answerable and on-topic (thought it might deserve a bit of editing).
I've seen discussion of chameleon questions before, but that usually concerns the case where open questions have been answered and the user is changing them in response to answers.
The right thing in this case would have been to for the user to ask a new question, but given that he hasn't, should the question be reopened, or the edit rolled back and the user encouraged to ask a new question?
(It's also possible, though far from apparent, that the user could be question-banned, and editing his old questions as a way of circumventing the ban).