General SEM Discussions

I've been trying to determine if OpenMx can be used to help with my optimization problem.

I'm very impressed with what I've read and am excited about the prospect of using it for my project. However, I'm not yet convinced it will help me do what I need and whether it is the right package for this work.

Hi.

When fitting a univariate model with continuous moderator, I keep getting positive log-likelihood (and naturally negative -2LL). The main variable is log transformed BMI. As far as I understand this is caused due to its small SD (SD=0.13 with mean=3.13). I saw in one thread (http://openmx.psyc.virginia.edu/thread/329) that it is recommended to avoid using variables with small variance. Would it be advised to use original BMI variable instead of log-transformed despite its skewness (1.22 vs 0.62 of the log-transformed)?

please help,,i need the procedures/ step by step in doing structural equation modeling..this is for my thesis..i need ur help..i don't how to start..i have already the data..

While it's relevant for both the Behavioral Genetics and OpenMX General Help forums, the overall question is rather general so I figured it should be posted here.

Our research group has done a wide variety of performance measurements on lab mice (running speed on treadmills, oxygen consumption, spontaneous activity, etc. etc. for each mouse). We also have survival and censoring information for each mouse. I believe that our measurements reflect several underlying biological processes that in turn determine the rate of aging in these animals.

Hello!
I've been working through Dorothy Bishop's tutorial, linked from this website here:
http://openmx.psyc.virginia.edu/wiki/ideas-simplified-manual-beginners-smb
or can be found in online form on her blog here:
http://dbtemp.blogspot.co.uk/2011/08/structural-equation-modeling-in-openmx.html

I found I was getting NaN std errors (see the comments at the bottom of the blog link above for the full discussion - I've paraphrased and extended the comments there in the question below).

Dorothy Bishop kindly replied with some suggestions, but thought that I should ask on this forum.

Hi!

I have run a structural model and am interested in deriving relative importance for each of the attributes that drive interest in my ultimate dependent variable. Is this possible to do?

Below is the model summary -

ATT1, ATT2, ATT3, ATT4 formed a latent variables L1
ATT5, ATT6, ATT7, ATT8 formed a latent variables L2
L1 and L2 are correlated and are predictors of DEP

How can I find out the contribution of ATT1 to ATT8 in predicting DEP? Please let me know. Thanks in advance for your help.