MIXTURE RANDOM COMPLEX combination PreviousNext
Mplus Discussion > Growth Modeling of Longitudinal Data >
Message/Author
 Mischa v Krause posted on Thursday, August 24, 2017 - 2:20 pm
Dear everyone,
I'm trying to fit a 3-class growth-mixture model with clustered data (families) and varying times of observations (age in years). I also want to predict the I and S factors using several binary variables (within each class).

It turns out that I get two error messages.

1. WARNING: THE SAMPLE COVARIANCE OF THE INDEPENDENT VARIABLES IS SINGULAR.

This appears as soon as I include any single covariate and at the same time TYPE is set to RANDOM (even if I don't use tscores in the model). It does not matter which covariate I use. I don't see any unit correlations or linear dependecies - especially since I only use one covariate, which also shows variance in all the classes.


2. WARNING: THE MODEL ESTIMATION HAS REACHED A SADDLE POINT OR A POINT WHERE THE OBSERVED AND THE EXPECTED INFORMATION MATRICES DO NOT MATCH.

This appears as soon as I model the clustered structure and thus cannot use the MLF-estimator. I have tried lowering the MITER and MCONV values and given starting values - this didn't help. MLF estimation unfortunately is not available with COMPLEX data. I do however get standard errors in the output.

I don't have any problems to run the RANDOM model with tscores using the MLF-estimator (without COMPLEX structure and predictors).

Do you have any ideas what else I could try?

Thank you
Mischa
 Bengt O. Muthen posted on Thursday, August 24, 2017 - 6:52 pm
Send the relevant files to Support along with your license number.
Back to top
Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: