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No user picture. EmilieRH Joined: 09/24/2020

Bivariate ACE model with moderator

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Hi all,

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No user picture. Leo Joined: 01/09/2020

ACE latent growth modeling

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Hello.

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No user picture. noamm Joined: 10/10/2018

Genetic correlations that doesn't make sense

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Hi, I'm trying to estimate a multivariate ACE model. I started by checking a correlated factors solution (umxACEv), but there are some correlations that just can't be real (e.g., 2.02).

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No user picture. lior abramson Joined: 07/21/2017

robust standard errors and CIs using umx

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Dear umx Experts,
I ran an ADE Cholesky model with 4 variables. When trying to obtain CIs for the one-headed paths (using the command umxConfint), I got weird CIs and the note "alpha level not reached" near some of the CIs. After consultation in the behavioral genetics forum, I understood that this the result of an optimization problem.

AdminRobK suggested that instead of looking at the CIs, I will try to get robust standard errors, then use mxSE() to get standard errors for the elements and form a CI from those standard errors

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

How do I get a CI on a parameter derived from a model?

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umxSummary reports the rA, rC, and rE for models. But this is done in the summary, and doesn't include CIs by default.

It’s computed as


solve(sqrt(I*A)) %*% A %*% solve(sqrt(I*A))

So you can add an mxAlgebra computing that into the model, then do mxSE on that


m2 = mxModel(m1,
mxAlgebra(name="ra", solve(sqrt(top.I*top.A)) %*% top.A %*% solve(sqrt(top.I*top.A)))
)
m2 = mxRun(m2)
mxSE(ra, m2)

That returns SEs, and CI= ± 1.96 * SE

best, t

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No user picture. noamm Joined: 10/10/2018

Correlated factors solution for umxACE

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Hi,

I'm using umxACE for a bivariate model. The current output is in the format of a cholesky model in addition to rG, rC, rE. Is there a way to get an output of the correlated factors solution? I know that I can easily calculate the estimates, but because they are not part of the model's output I didn't succeed in getting CI's for the calculated estimates (or the r's). Is there a way to get these (as these are more intuitive for presenting)?

Thanks for all the help!

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No user picture. noamm Joined: 10/10/2018

umxSexLim - heritability doesn't match correlations

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umx

Hello,

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No user picture. Leo Joined: 01/09/2020

Obtain CIs on genetic correlations

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I'm interested in obtaining the CIs of the genetic correlations using umx. Running umxCi prior to umxsummary does only provide the CIs for the different paths. Can anyone help me?

Thanks in advance.

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Picture of user. paulT Joined: 11/03/2017

default constraints in multi group model?

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I am a new OpenMX|umx user and am trying to fit a multigroup model. I have fitted two separate umxRAM models (one for each group) and then tried to repeat using the 'umxSuperModel' command. I seem to get very different model results between the multi group model and the separate group models. In the single groups models, there are fewer significant paths in one group, but the multi group appears to have identical significant paths (only varying between group in path weight magnitude)?

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No user picture. benruk Joined: 12/09/2019

Multiple Moderators

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umx

Hello,
some days ago I read the paper by Shaun Purcell (2002) "Variance Components Models for Gene-Environment Interaction in Twin Analysis" and I'm especially interested in modelling a three-way interaction (GxExE). So, for example, the genetic effect may be moderated by the socioeconomic status and by age, so that the additive genetic variance component is:

$$
(a+\beta_{Age}M_{Age}+\beta_{SES}M_{SES}+\beta_{AgexSES}M_{Age}M_{SES})^{2}
$$

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