Hi, as the WLS implementation evolves, it would be great to allow definition variables with WLS!
I agree completely! I don't think we need WLS with definition variables working for the first release of WLS, but it would be good to have a definition variable capability in mind while ironing out the user interface for the rest of WLS.
How would this work? WLS is based on a moment matrix, while definition variables by definition (ha!) must be implemented row by row. I'd love for it to exist, but we'd have to invent it.
A work around would be making a multiple group WLS, such that each group is one level of the definition variable. Kind of a pain, though.
The simplest foot in the door here is ULS. If it's ULS, then we could definitely in principle have definition variables. We can know what that means now. What other kinds of WLS mean with definition variables is an open question.