OpenMx General Help
PCFLaw
Joined: 08/26/2020
2-class growth mixture model: adding time-invariant covariates & viewing class probabilities
I am wondering if I can get some help on a 2-class growth mixture model I'm having trouble with (script and example dataset attached). The model describes a single linear trajectory across 8 time-points (t1-t8). I'm new to OpenMx and I've looked through this forum/other sites but I'm at a loss. I'm trying to (i) add 3 time-invariant covariates ('Sex', 'Age', 'pooled_VA') to the 2-class growth mixture model and (ii) view the class probabilities for each case.
davide
Joined: 03/13/2020
Constraints
I'm trying to construct a model where I need to implement a constraint across groups. My model is of the form:
Mxgroup1 {
matrix A
matrix B
}
Mxgroup2 {
matrix C
matrix D
}
And I want to employ the constraint A + B = C + D
Any ideas how I can do this?
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kaje
Joined: 06/05/2019
factor scores curiosity -- comparing OpenMx and lavaan
when estimating a very simple latent variable autoregressive panel (AR(1)) model with an integrated trend component, I noticed that the factor scores based on the regression method do not include the trend (or maybe they are a kind of detrended). I'm wondering whether there maybe is a reason or a rationale behind this that I don't see. If you add the model implied means to the factor scores, you get the same factor scores as when using lavaan.
Here is a minimal working example:
Veronica_echo
Joined: 02/23/2018
OpenMx does not work after updating R 3.6
After updating R3.6, OpenMx doesn't work. My OS is macOS Mojave version10.14.5. I am pasting the error message I got. Any advice about it? Thanks in advance.
Veronica
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Veronica_echo
Joined: 02/23/2018
Error message of mxTryhard() with NPSOL optimizer
I installed OpenMx2.11 thought source('https://openmx.ssri.psu.edu/software/getOpenMx.R') and wanted to switch optimizer by mxOption(NULL,"Default optimizer","NPSOL"), but I got error message
Error in runHelper(model, frontendStart, intervals, silent, suppressWarnings, :
NPSOL is not available in this build. See ?omxGetNPSOL() to download this optimizer
I also had the same error message when I tried to use cluster to run the model.
How can I fix it? Any advice would be appreciated!
Veronica_echo
Joined: 02/23/2018
Error message when using get() to return values of OpenMx object
I am trying to return values of an OpenMx object from optimized mxModel by get() (more details could be found in attached). Is there any other way to return the value of an OpenMx object by string? Thanks in advance.
Veronica_echo
Joined: 02/23/2018
Remove path from an existed model
I would like to remove one factor, say "IQ2", from a CFA (script is below). Does it work if I rewrite the model as
cfa2 <- mxModel(cfa, "one factor", mxPath(from = "Q2", to = "Q2", arrows=2, values = 0, free = F),
mxPath(from = "Q1", to = "Q2", arrows=2, values = 0, free = F),
mxPath(from = "Q1", to = observed, free = F, values = 0)
)
Is there any more convinience way to remove path?
Thanks in advance!
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Veronica_echo
Joined: 02/23/2018
bootstrap coverage probability and the bootstrap replication
I am conducting a simulation study of a growth model and would like to evaluate the bootstrap CP of it. I kept the simulation replication as 1000 and set bootstrap replication as 1000 and 2000, respectively. The results seemed wiered, since the CPs of bootstrap 1000 (all of them were located between (0.93, 0.97)) were much better than those of bootstrap 2000 (some CPs were quite low, say 0.86). Any advice about this issue? Should I increase the bootstrap replication to a larger number, say 5000? Thank you in advance.
Veronica_echo
Joined: 02/23/2018
How to exclude warnings from simulation study?
Veronica_echo
Joined: 02/23/2018
parallel computation in linux cluster
I want to conduct several 10,000-simulations for an OpenMx model in Linux cluster. I have over 20 parameters in the model and for each parameter, I need 1000-bootstrap confidence interval to test the coverage. I've add lines in below screenshot, and there are 16 cores available for OpenMx. Even though, the simulation may take about one month at my best guess. Could someone kindly advise some other ways to speed up my simulations? Thanks in advance.
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