OpenMx Help

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No user picture. CharlesD Joined: 04/30/2013

Error : The RAM model 'blahblah' does not contain any paths

This occurs after I change the data associated with an otherwise working matrix specification model... I don't think it should :)

Posted on
Picture of user. Charlotte Joined: 07/02/2012

Simplex model & sex differences

Dear all,

I am working on a simplex script in openMx. There are quantitative and qualitative sex differences for my phenotype, so I estimate separate paths for males and females and I would also like to freely estimate the dos correlations between the latent As. However, I am struggling with the transmission paths.
Probably, someone else has already dealt with this. I would like to know whether there are any simplex scripts available that take into account sex differences?

Regards
Charlotte

Posted on
No user picture. ywyh Joined: 09/25/2014

identifying bivariate outliers

Hi,

I am trying to detect and identify bivariate outliers in a dataset using OpenMx, in order to see whether specific outliers have significant contribution. Preferrably the output would be like that of %p in old Mx.
(i.e. 8 columns with:
1) -2lnL,
2) Mahalanobis,
3) estimated Z,
4) number of observations in data set,
5) number of data points in vector,
6) optimization details,
7) whether or not likelihood was calculable, and
8) model number if there are multiple models)

Posted on
No user picture. yoosoo Joined: 06/19/2014

Multilevel SEM with complex sampling

Dear all,

Would you confirm if OpenMx supports multilevel SEM on complex sampling survey data, with categorical outcome? (each datapoint has different weight)

Thank you!

Posted on
No user picture. rl Joined: 08/26/2014

Categorical Data in both independent and dependent variables

I have a data set with six binary variables, which I am trying to determine the temporal relationship. I was using lavaan R package, where they suggested to use dummy variable for endogenous variables (independent) and use ordered for exogenous (dependent variables). I was using the model as described in pdf file. I have gotten following results:

lavaan (0.5-16) converged normally after 31 iterations

Number of observations 51

Estimator DWLS Robust

Posted on
No user picture. CharlesD Joined: 04/30/2013

Another excess memory usage problem - sudden spike when using csolnp

CSOLNP is working quite nicely in general, but I have a few circumstances where things go dramatically wrong and crash my machine (hard reboot needed) due to excess memory usage if I don't notice fast enough. This doesn't occur when using npsol. With the earlier memory usage issues ( http://openmx.psyc.virginia.edu/thread/2551 ) memory usage increased gradually, but in this case it seems much more sudden.

A problem model can be downloaded from:
https://www.dropbox.com/s/kgpsualdlnaowhs/memprobmodel.RData?dl=0

test <- mxRun(memprobmodel, intervals=T)

Posted on
No user picture. fife Joined: 07/01/2010

Problem getting parameters from model

Hi all,

I hope I'm just not seeing something, but the way you extract coefficients and fit statistics seems to have changed. It used to be that I could extract the coefficients by typing:

summary(model)$parameters

Posted on
No user picture. CharlesD Joined: 04/30/2013

matrix logarithm function for mxAlgebra

Any chance of this being implemented at some point? Would seem to be consistent with the omxExponential implementation. Currently I optimize some free parameters over the range 0 to -inf, which is exponentially scaled, and I suspect this probably poses optimization difficulties....

Posted on
No user picture. metavid Joined: 06/23/2014
Posted on
No user picture. yoosoo Joined: 06/19/2014

Does OpenMx support multilevel, ordinal/binary outcomes/indicators with sampling weights?

Hi,

I am hoping to perform a multilevel SEM on complex-sampling survey data, with known weight and binary outcome and ordinal independent variables.

Similar posts on this forum don't seem to support that this is simple to do on OpenMx, but any advice would be much appreciated. (http://openmx.psyc.virginia.edu/thread/2348, http://openmx.psyc.virginia.edu/thread/861#comment-form)

Thank you.