OpenMx Structural Equation Modeling

Posted on
Picture of user. tbates Joined: 07/31/2009

fit@output$confidenceIntervals doesn't give estimate, just lbound and ubound

hi all,
If you do "summary(fit)$CI" you get the upper, lower, and estimate:
lbound estimate ubound
top.a_std[1,1] -0.68048731 -0.6216239 -0.5515234

but "fit@output$confidenceIntervals" gives just the upper and lower:
lbound ubound
top.a_std[1,1] -0.68048731 -0.5515234

Because summary takes ages to run on big models, it would be nice if "fit@output$confidenceIntervals" had the estimate in there as well: Also good for consistency.

Best, t

Posted on
No user picture. spanosal Joined: 06/02/2010

Constraint Model

Can anyone direct me to a script indicating how to run a constraint model? I am combining two twin data sets and want to run a fully constrained and fully unconstrained model in order to know if the two samples can be combined. How can I tweak my multivariate Chlolesky to do this?

Posted on
Picture of user. suzannejak Joined: 01/06/2010

estimation constraint when analyzing correlation matrix

Hello,

When analyzing a correlation matrix, do I need to put a constraint to the estimated Sigma so that its diagonal equals identity during optimization? As in Mx? Or has this been taken care of already in openMx?
Thanks in advance!

Suzanne

Posted on
Picture of user. mdewey Joined: 01/21/2011

Modification indexes/indices

I am starting a new thread on this but see
http://openmx.psyc.virginia.edu/thread/831
for background.

I am still attempting to replicate the results from Sorbom's paper using the code posted by Rine and some of the new options to mxRun outlined in the old thread. I am attaching three files.
mi.r contains my code for modification indexes
sorbom.r creates the correlation matrix from one of the examples in Sorbom's paper and runs it
sorbom.txt is the resultant output showing the value of mi I get,

Posted on
Picture of user. tbates Joined: 07/31/2009

CIs: updating mxCI in a model

hi,
I have a model with existing CIs

fit1a
...
@intervals : 'top.a_std', 'top.c_std', and 'top.e_std'
...

I want to delete those, and run with just 1 request, so I tried
fit1b= mxModel(fit1a,mxCI(c("top.e_std[1,2]")))
but this seems to add the CIs onto the end of the list (rather than stamp on the old list)

Posted on
No user picture. berlinator Joined: 06/09/2011
Posted on
No user picture. Sabha Joined: 05/18/2010

GUI option for OpenMX

I am just wondering if any one developing a GUI for OpenMX.

Atleast an option in future would be of great value.

Posted on
Picture of user. wuhao_osu Joined: 09/07/2010

How to obtain saturated model fit?

Hello, guys,

When using the MLObjective, how to obtain the saturated model fit? Is it somewhere in the output slot? If discrepancy function value can be found, that is even better. I think most softwares when analyzing a sample covariance matrix would return the discrepancy function value.

Thanks.

Hao

Posted on
No user picture. jakob Joined: 03/09/2011

faster mxRun for multiple runs

Hello everybody,

I'm new at the forum and a newbee with OpenMx and SEM modelling, so my excuses if there may be some stupid questions I gonna ask :-)

Here comes my Problem: I try to write a script that automatically searches the best free parameter and fits it until all significant parameters are fittet. Just like the OU AM option of LISREL. However, it takes quite a while over it, and with more complex models its probably going to take days...

What I'm currently doing is in words and pseudo-code
1. compute the log-likelihood of a null-model:

Posted on
No user picture. rlucas Joined: 11/17/2009

How to change labels for multiple submodels

My question probably reflects my inexperience scripting in R, but I thought I'd give it a shot here.