Hi,
I am new to OpenMx and trying to use it for twin study (monozygotic vs dizygotic twins). I have some questions and hope someone may help me with the following questions.
I tried the following two scripts:
https://openmx.ssri.psu.edu/svn/tags/stable-1.2/demo/UnivariateTwinAnalysis.R
https://openmx.ssri.psu.edu/svn/tags/stable-1.2/demo/UnivariateTwinAnalysis_MatrixRaw.R
I knew their input data were different, but is there any difference for data processing steps between these two?
I see in order to decide between ACE and AE models, the aforementioned scripts do the log-likelihood ratio test at the end of the script. They got the difference between the log-likelihood of AE model and ACE model. But how could I decide which model I should choose based on this value? Should I do chi-square test using this value and degrees of freedom?
Also, is there any script available online which could also calculate the p-value for the parameters a2, c2 and e2?
Thank you very much!