OpenMx Help

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

Fake Latents

Hi,
Snuffling around in MxPPMLR I see
# IN DEVELOPMENT
# Fake Latents
# There are multiple ways to specify the error variance terms. There is the
# usual, direct way of allowing the term in the S matrix to be free, but it
# can also be specified using latent variables.
#
# This segment adjusts the model so that all error variance is specified using
# only the S matrix, without any latent variables

This raised a question for me.

I guess this is designed to do change this:

Into this:

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

AIC etc in multi-group RAM models

hi all,
Running a 2 group RAM model. Both sub-models return their fit indices in summary(), and the supermodel runs fine, with a summed objective.

However... while the supermodel knows about the submodel's observations etc (as shown in the print out below) it doesn't compute an AIC for the the supermodel

Bug/Missing code?


observed statistics: 156
estimated parameters: 79
degrees of freedom: 77
-2 log likelihood: 46372.74
saturated -2 log likelihood: NA
number of observations: 6000
chi-square: NA
p: NA
Information Criteria:

Posted on
No user picture. brauer Joined: 01/28/2012
Posted on
No user picture. koak Joined: 05/10/2012

Bivariate or multivariate correlated factors model script

I am super new to twin analyses, R, Mx and the whole shebang ... I am wondering if anyone has a script for a bivariate or multivariate correlated model. I have been using the Cholesky Decomposition, Independent Pathways and Common Pathways models to look at my multivariate data and would like to be able to at the data from a correlated factors perspective.

Any help much and greatly appreciated!

Karen

Posted on
No user picture. brauer Joined: 01/28/2012

Lagrange Multiplier Test

Hi, is there a way to get the Lagrange Multiplier Test with OpenMx? I am usually not a fan of this type of data-driven test but I am currently analyzing a dataset where a LM Test might help me understand what is going on. I am running a four-factor CFA model with three indicators. The fit is OK but not great. The correlation residuals tell me that I am drastically underestimating the relationship between one indicator of the first factor and one indicator of the second factor.

Posted on
No user picture. brauer Joined: 01/28/2012

How to get the correlation residuals with the new version of OpenMx?

Hi,

I recently downloaded the most recent version of OpenMx. Since then I am no longer able to get the model-implied covariance matrix, and therefore, the correlation residuals. Before, the following script would get me the correlation residuals:

residuals <- cov2cor(covmatrix) - cov2cor(modelfit$objective@expCov)
round(residuals, digits=4)

My data are in "covmatrix", a symmetric covariance matrix. The result of the mxRun is stored in "modelfit")

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

RAM estimation from covariance matrix where ns differ per cell

hi all,

When mxData is a cov or cor matrix, numObs is just one number.

Quite often the cells in a covariance matrix could take advantage of different numbers of observations.

Two questions: has anyone made RAM models with an "numObs" matrix to give a per-cell n? And second, are the assumptions of a covariance-based model violated if all data do not come from complete subjects?

Posted on
No user picture. adstaple Joined: 01/06/2010

Error: in slot(model, name) : no slot of name ".forcesequential" for this object of class "MxModel"

I previously ran analyses in OpenMx and saved the R workspace so that I could get the information at a later date.

The Error: in slot(model, name) :
no slot of name ".forcesequential" for this object of class "MxModel"

Occurs when I call
summary(mxModelFit)

On a Mac running 10.7.3, R v. 2.14.2, OpenMx v. 1.2.3-2011

However, when I use the same call (after loading the same R workspace file) on a different Mac running 10.7.3, R v. 2.14.0, OpenMx v. 1.1.2-1818, I do not get the error.

Posted on
Picture of user. Julia Joined: 03/29/2012
Posted on
Picture of user. Julia Joined: 03/29/2012

64-bit version of OpenMx

Hello.

I read that 64-bit version of OpenMx is under development. Do you have any time frame when approximately it will be available? I am just running an analysis that take a LOT of time since 32-bit R uses only 4 GB of RAM.
Is there an advantage of installing OpenMx on a 64-bit Windows machine even though using 32-bit OpenMx?

Thank you beforehand.
Julia