Apologies if this is answered elsewhere, but I was wondering if OpenMx allows estimation of random factor loadings at the within-level in a multilevel confirmatory factor analysis.

A less important aside: has anyone been able to successfully include a nonlinear constraint in a two level CFA or SEM with latent variables?

Right now, OpenMx does not allow random factor loadings in a multilevel CFA. You can have definition variables deterministically change the factor loadings (including algebraic expressions involving free parameters and definition variables), and you can estimate a different factor loading for each level 1 unit. However, in both these cases, the factor loadings are fixed effects, not random.

As for using nonlinear constraints,

`mxConstraint()`

works regardless of the kind of model, so there should be no issues. In many cases, it's computationally better to use`mxAlgebra()`

to set parameters to be the result of the algebra instead of using`mxConstraint()`

, but it should work either way.