# Longitudinal SEM and Latent Growth Curves

## Individual slope and intercept estimates?

My inclination is to get factor score estimates for the intercept and slope factors, but when I do this using mxFactorScores(), I get an error message:

"Error: In model 'FactorScoresLGCM_N' the name 'fscore' is used as a free parameter in 'FactorScoresLGCM_N.Score' but as a fixed parameter in 'FactorScoresLGCM_N.Score'.

- Read more about Individual slope and intercept estimates?
- 6 comments
- Log in or register to post comments

## Structured latent growth curve with definition variables

Error in value[rows[[i]], cols[[i]]] <- startValue :

incorrect number of subscripts on matrix

## LCS: Effect of a time-independent predictor on a covariance

## How to use the EM algorithm with a nonlinear latent growth curve model?

$$y_{obs} = \frac{diff}{1+e^{\frac{\beta - time_i}{\gamma}}}, $$

## RI-CLPM: covariates and scaling

- Read more about RI-CLPM: covariates and scaling
- 1 comment
- Log in or register to post comments

## Cross-lagged model issues

I have a cross-lagged model that I have run using the code below:

- Read more about Cross-lagged model issues
- 15 comments
- Log in or register to post comments

## negative variance in factor representing change in anxiety (latent factor)

I'm having trouble with a model investigating change in anxiety over time. In the future, I will be building out a more complex model with other factors predicting change in anxiety over time, but I'm now just at a step before that looking into a model with only change in anxiety over time--only for two time points.

## How to implement FIML estimation in OpenMx?

I am running this code to conduct LGCM prior to GMM.

I was wondering if there is a way of implementing FIML instead of ML in my code.

This is because my data has a lot of missingness by design (longitudinal data) and is not normally distributed.

Many thanks!!!

require(OpenMx)

?MxFitFunction

fitFunction <- mxFitFunctionML(rowDiagnostics=TRUE)

mxOption(NULL,"Default optimizer","SLSQP") ### to avoid msg error: https://openmx.ssri.psu.edu/node/4238

- Read more about How to implement FIML estimation in OpenMx?
- 1 comment
- Log in or register to post comments

## Help in understanding notation for NO-GROWTH MODEL (OpenMx) and ERROR message

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.

## More questions about the magic of LGM with use of age definition variables

#### Pagination

- Page 1
- Next page