Hi there,

I am extremely green to openMX, R, and SEM in general. I've perused some of the introductory materials, which have been helpful. The model I'm trying to run is REALLY simple -- hopefully a refreshing change for the users of this message board -- so I've actually spent a bit of time trying to find a script online that I can use by making some simple edits. I have a group of MZ and DZ twins, and I want to run an ACE model to estimate causes of variation for one (just one!) categorical variable. For each pair of twins, the variable is named "twin1" and "twin2", and it can be "1" or "2".

I attempted to use the script that's on this page ("ACE Model Twin Analysis", using my data and my variable names:

http://openmx.psyc.virginia.edu/docs/OpenMx/latest/GeneticEpi_Matrix.html

However, I am getting the following error message when I attempt to run the model:

Running twinACE

Error: The data object 'MZ.data' contains an observed matrix that is not of type 'double'

Could someone tell me what I might be doing wrong and overlooking? I realize this is somewhat vague, but unfortunately, it's where I'm at right now in my understanding...

Thanks!