Trouble reading longitudinal data PreviousNext
Mplus Discussion > Growth Modeling of Longitudinal Data >
 Elisabeth de Moor posted on Saturday, May 27, 2017 - 1:36 pm
Hi Drs. Muthen,

For a project with longitudinal data, I've been trying to read in data from a two wave study to fit some latent growth models. However, for some reason when I run a basic analysis, all the means and covariances look nearly identical and I get a singular covariance matrix. When I run descriptives in SPSS, the means and variances look normal.

In short what I've done:
I first imputed plausible values in an R package using IRT for the variable of interest. In SPSS I have transformed the two wave data to age based variables so that I have a variable for each whole age in the dataset. The means of these age based variables look normal in SPSS. When I convert the file to csv/.dat and open te file in Mplus, the means, covariances and variances become as I described before.

Do you have any idea what might be the problem that causes the change in means and covariances/variances?
 Linda K. Muthen posted on Sunday, May 28, 2017 - 9:32 am
Please send the output, data set, and your license number to
Back to top
Add Your Message Here
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Options: Enable HTML code in message
Automatically activate URLs in message