Fri, 05/06/2011 - 10:24

Hi all,

I have been working with OpenMx in R with some success over the past several months after attending the Boulder conference last March. The scripts provided at the workshop have been very helpful, but I can't seem to find examples for independent and common pathways models. Any help would be greatly appreciated.

Thanks,

JM

Common and independent pathway models are the joining of factor models and ACE-type models, both of which are covered in the documentation. Let's say that you're interested in a common pathway for a single factor solution on some set of twins. Your factor model would look very much like the two-factor model example in the documentation, with the factor for twin 1 (x in the example) constrained to be equal to the factor for twin 2 (y in the example) through equality constraints on loadings and residual variances. The covariance between the factors is then given by the ACE model in the genetic epidemiology example.

Look at this thread about ACE models for latent variables for more information: http://openmx.psyc.virginia.edu/thread/789

Thanks for the thoughts. I am quite a novice at this so I was hoping for something more practical, as I saw that there are example scripts for classic mx so I thought maybe there was a place for example scripts for openmx. I'll see what I can make of the references you provided but if anyone has an example of these models in openmx I'd greatly appreciate it.

Thanks