OpenSEM Forums
benruk
Joined: 12/09/2019
Covariate Effect in Liability Threshold Model
Hello,
I want to write a script for a GxE-interaction with an ordinal outcome and a continuous moderator and was looking for some scripts that include a covariate effect on an ordinal outcome variable.
In this search I found a [script](https://static1.squarespace.com/static/58b2481a9f7456906a3b9600/t/5d9c0be7b3de004d53e6456b/1570507752071/oneACEoa.pdf) by Hermine Maes where she models the effect of the covariate (age) on the mean of the liability distribution of the outcome variable.
MIRELA
Joined: 04/03/2020
Biometrical model fitting
My question concerns choosing the best fitting model. Given the twin correlations in a given phenotype (rMZ = 0.50, rDZ = 0.34), it seems that the model to be tested should be the ACEmodel (because rMZ < 2rDZ).
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szellers
Joined: 04/04/2018
Cohort Covariate and ACE Estimates
Hi all,
I've been playing around with various ways to include a cohort covariate in a single-factor model. I've tried four approaches, three of which have pretty consistent results and the fourth, which is fairly different. I've attached the four scripts here, as well as a table of selected output (ACE estimates with CIs, factor loadings, and expected means for observed variables).
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lior abramson
Joined: 07/21/2017
best way to (systematically) fit an ADE model
Dear Forum,
I am trying to fit a longitudinal Cholesky model (two variables in two time-points) with the umxACE and umxModify commands from the umx package.
quino
Joined: 03/12/2020
Mis-specification and model fit interpretation of univariate ACE
Dear all,
I am new to statistical modelling for genetic analysis and after conducting a round of univariate analysis (prior to a future multivariate one) using the umxACE function I have a few questions I would like to ask for help with.
benruk
Joined: 12/09/2019
Test Moderation of Standardized Variance Components
Hello,
since in the conventional moderated ACE model proposed by Purcell it is only possible to test whether there is a significant moderation of the unstandardized genetic, shared and unshared variance components in a phenotype, I was wondering whether it is also possible to test if there is a significant moderation of the standardized variance components.
JuanJMV
Joined: 07/20/2016
Modified CP model
Dear all,
I am trying to fit a model (I am not sure if it will be possible) like the one in the attached figure.
I am trying to do it by modifying this script (CP model with one latent factor):
# Fit Common Pathway ACE Model
# ------------------------------------------------------------------------------
nl <- 1
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lior abramson
Joined: 07/21/2017
umxsexlim command-different results in each run for the exact same command
Hello,
I am trying to conduct a multivariate sex-limitation model. I am not sure why, but when I run the exact same command I get different results in each run (and in some of the runs, the results don't really correspond with the raw data and don't make sense).
I assume that this is the result of an unstable solution. However, I don't get any warning messages that indicate there is anything wrong, or that could direct me what to do.
The script is attached. Do you have an idea what could be the problem?
YiTan
Joined: 10/08/2014
Bivariate ACE model with covariates for ordinal variables
Hi,
I couldn't find any existing OpenMx codes to conduct bivariate genetic modelling for ordinal variables with covariates, so I've adapted Hermine Mae's twoACEvo.R code (bivariate ACE model for ordinal variables) by adding covariates to the code. I thought it was quite straightforward, but when I ran the code I got the following error:
Error in as.vector(data) :
no method for coercing this S4 class to a vector
YiTan
Joined: 10/08/2014