OpenMx Help
iana
Joined: 10/16/2021
How to handle missing data in multilevel meta analysis & mutilevel TSSEM?
Hi Mike and all,
I'm working on a meta-analysis examining the mediators between attachment and intimate partner aggression. I would like to use two methods to meta-analyze the data. The methods include 1) three-level meta-analytic models (Assink & Wibbelink, 2016) and 2) three-level TSSEM (Wilson et al., 2016). Both are random-effects models.
hansfredriksunde
Joined: 12/10/2021
Problems with variance estimation with missing continuous data: WLS seem to replace NA with 0
Hi everyone
I'm currently building an extended children-of-twins-and-siblings model that will have dichotomous data in the child generation and continuous data in the parent generation. The model includes both twins and their partners (co-parents), so that assortative mating can be taken into account. The number of free parameters (>10) make maximum likelihood unfeasible when using dichotomous data (i.e., the processing time is too long). I therefore use the WLS fit function instead.
kme
Joined: 04/27/2022
Vector of individual scores (logL derivatives)?
Is there a way to obtain the vector of individual logL derivatives? I could find stuff about finding the Hessian, and individual likelihoods, but not the individual scores.
pehkawn
Joined: 05/24/2020
Identification of CFA with continuous vs. ordinal variables
As a step to building a larger SEM, I am currently trying to fit a MIMIC CFA with ordinal indicators.
As demonstrated in the sample script and dataset, the model (using ML) with continuous variables the model is identified and no error is thrown.
If I recode variables as ordinal, and add thresholds to the model I get the error messages differing based on fit function.
cllstrauss
Joined: 04/07/2022
Random factor loadings in MCFA
Apologies if this is answered elsewhere, but I was wondering if OpenMx allows estimation of random factor loadings at the within-level in a multilevel confirmatory factor analysis.
A less important aside: has anyone been able to successfully include a nonlinear constraint in a two level CFA or SEM with latent variables?
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lf-araujo
Joined: 11/25/2020
How to go past a model implied cov not positive definite error?
Hi all,
I am trying to specify the CLPM in the attached figure (It's an extension of Zyphur's 2020 general CLPM, but with PGSs). I specified both using lavaan syntax in umx and matrix algebra (first time, hope it is correct, but looks like so). It is identified, the model runs ok. But when I try to get power or the ncp statistic it fails, as the model's implied cov is not positive definite.
- What can I do to avoid this? lbounds and ubounds will help me there?
Lavaan code:
eitaknam
Joined: 03/27/2022
NPSOL is not available in this build
I experienced the below error message when I am running the ACE model:
==========================================================
Running oneSATc with 10 parameters
Error in runHelper(model, frontendStart, intervals, silent, suppressWarnings, :
NPSOL is not available in this build. See ?omxGetNPSOL() to download this optimizer
==========================================================
This is the version of my MacOS and OpenMX:
- Read more about NPSOL is not available in this build
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eitaknam
Joined: 03/27/2022
NPSOL is not available in this build
I experienced the below error message when I am running the ACE model:
==========================================================
Running oneSATc with 10 parameters
Error in runHelper(model, frontendStart, intervals, silent, suppressWarnings, :
NPSOL is not available in this build. See ?omxGetNPSOL() to download this optimizer
==========================================================
This is the version of my MacOS and OpenMX:
- Read more about NPSOL is not available in this build
- 1 comment
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ou.yang@unimel…
Joined: 03/19/2022
Algorithm underlying omxMnor
Dear all,
I am currently using omxMnor to calculate the multivariate normal integral in my paper. Wonder what is the underlying algorithm implemented by omxMnor. Any references would be greatly appreciated!
Cheers,
Ou
- Read more about Algorithm underlying omxMnor
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pehkawn
Joined: 05/24/2020
Fitting model with three latent variables and 16 ordinal and four continuous indicators
I am having trouble fitting a SEM with three latent variables with the following specification: An endogenous latent variable, created from four continuous manifest indicator variables, is regressed on two exogenous latent variables created from multiple ordinal manifest indicator variables. Prior to creating the SEM model I ran a CFA model, with similar specification, but where the three latent variables covary. I used the resulting factor loading values as a starting point for the SEM model.