Attachment | Size |
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OpenMx script [6] | 111.28 KB |
result of path diagram with OpenMx script (from the book) [7] | 117.19 KB |
Hello,
I´m having a hard time understanding the OpenMx notation from this handbook "Growth Modeling" (Grimm, Ram & Estabrook, 2017).
The authors compare the script from MPlus and OpenMx with regard to the specification of a no-growth model (attached as pics). While in Mplus is pretty straightforward, I don´t understand why the latent factor variance (psi_11) and the indicators residual variances are set at 80 and 60 respectively in the OpenMx script.
As we are estimating a no-growth model, why don´t we simply put a 1 to express the fact that these parameters are fixed? Where do these values come from??
In addition, I have tried running this model on my data with exactly the same code just changing the names of variables.... and I obtain this error message... does anybody know why??
Error: Nice try, you need to add '2' to either manifestVars or latentVars before you can use them in a path.
MANY THANKS