FMM/LPA Syntax problem PreviousNext
Mplus Discussion > Latent Variable Mixture Modeling >
Message/Author
 Anonymous posted on Tuesday, January 31, 2006 - 8:27 am
Hello,

I am really quite new to the whole mplus-thing, so please forgive me naivité.

I want to specify some kind of 'factor mixture model' or 'latent profile analysis' and have some questions concerning syntax-writing. I have seven continous variables which I assume to have specific means, variances and covariances in two (or more) unobserved groups. Because by default Mplus (Version 3.0) assumes a) variances of observed to be equal, b) covariances of observed variables to be zero in these classes, I need to override these defaults. So my syntax goes as follows (cases are weighted):

TITLE: factor-mixture-model / latent profile analysis, englisch;
DATA:
file is englisch.dat;
format is 1f10 8f4;
VARIABLE:
names are idstud ekenntn bedemut bedevat eunter umgange werte eltinte sampwgt;
usevariables are ekenntn bedemut bedevat eunter umgange werte eltinte sampwgt;
classes = c (2);
weight is sampwgt;
ANALYSIS:
type = mixture;
MODEL:
%Overall%
ekenntn with bedemut bedevat eunter umgange werte eltinte;
bedemut with bedevat eunter umgange werte eltinte;
bedevat with eunter umgange werte eltinte;
eunter with umgange werte eltinte;
umgange with werte eltinte;
werte with eltinte;
ekenntn bedemut bedevat eunter umgange werte eltinte;
%c#1%
ekenntn bedemut bedevat eunter umgange werte eltinte;
ekenntn with bedemut bedevat eunter umgange werte eltinte;
bedemut with bedevat eunter umgange werte eltinte;
bedevat with eunter umgange werte eltinte;
eunter with umgange werte eltinte;
umgange with werte eltinte;
werte with eltinte;
%c#2%
ekenntn bedemut bedevat eunter umgange werte eltinte;
ekenntn with bedemut bedevat eunter umgange werte eltinte;
bedemut with bedevat eunter umgange werte eltinte;
bedevat with eunter umgange werte eltinte;
eunter with umgange werte eltinte;
umgange with werte eltinte;
werte with eltinte;
OUTPUT:
tech1;

Question 1: Do you think, my syntax matches my assumptions mentioned above? Especially: Do I have to free variances and covariances in the %Overall% part of the Model-statement? To me, that seems a reasonable thing to do, since I expect my variables to covary in the whole sample.

Question 2: However, the estimation of the model above won't terminate. What Mplus (Version 3.0) tells me is:

THE LOGLIKELIHOOD DECREASED IN THE LAST EM ITERATION. CHANGE YOUR MODEL
AND/OR STARTING VALUES.

THE MODEL ESTIMATION DID NOT TERMINATE NORMALLY DUE TO AN ERROR IN THE
COMPUTATION. CHANGE YOUR MODEL AND/OR STARTING VALUES.

I already tried starting values for the intercepts, as you suggest in your example 7.10 but that leads to another error message concerning the ESTIMATED OVARIANCE MATRIX FOR THE Y VARIABLES, which IN CLASS 2 COULD NOT BE INVERTED. Did I get something wrong? I don't think, my model is so complex after all, but fitting it just won't work...

Thanks in advance for your advice
 Linda K. Muthen posted on Tuesday, January 31, 2006 - 9:21 am
Because the Mplus defaults can vary depending on the type of model being estimated, I suggest looking at your results to see if you are estimating the parameters that you intend. Even non-converged results will list the parameters that are being estimated.

I wonder if you were successful with the Mplus default model. If you have success with this, then you can relax the defaults but not all at the same time. I also suggest using Version 3.13 which is the current version. There have been many changes since Version 3. If you continue to have these problems which a data dependnet, send your input, data, output, and license number to support@statmodel.com.
 Vlad posted on Wednesday, February 24, 2010 - 4:19 am
Hello,
When I run the FMA in the output file I have f and c_f, among other variables. As far I understood, f corresponds to the latent variable. Then, What about c_f? Also, I have the 2nd stage in my work. In this stage what values f/c_f should be used?

regards,
V
 Linda K. Muthen posted on Wednesday, February 24, 2010 - 9:33 am
f are factors scores mixed over classes. c_f are factor scores based on most likely class membership. Regarding which to use, that depends on your research question. It is also related to measurement invariance. The following paper discusses the topic of measurement invariance for different FMA models:

Clark, S.L., Muthén, B., Kaprio, J., D’Onofrio, B.M., Viken, R., Rose, R.J., Smalley, S. L. (2009). Models and strategies for factor mixture analysis: Two examples concerning the structure underlying psychological disorders.
 Vlad posted on Wednesday, February 24, 2010 - 10:18 am
Thank you!
 Aleksandra Kauin posted on Thursday, April 07, 2016 - 9:48 am
Hi Everyone! I am trying to do a 3-Class-LPA with this syntax, however I constantly receive the follwing error message:
*** ERROR in MODEL command
Unknown class label: %C#1%

Do you have any suggestions?
This is an excerpt of my syntax:

title: LCA IRI
data: file = XXX.dat;
variable:
names = childid IRI1
IRI2 IRI5 IRI6 IRI8 IRI9 IRI10
IRI11 IRI16 IRI17 IRI20 IRI21
IRI22 IRI23 IRI24 IRI25 IRI26
IRI27 IRI28 IRI3_r IRI4_r IRI7_r
IRI12_r IRI13_r IRI14_r IRI15_r
IRI18_r IRI19_r;
missing = all(9999);
usevar =
IRI6 IRI8 IRI10 IRI11
IRI17 IRI21 IRI24 IRI27
IRI28 IRI25 IRI3_r IRI13_r
IRI15_r IRI19_r;
classes = class(3);
analysis:
Type = Mixture;
model:
%OVERALL%
%C#1%
IRI6 IRI8 IRI10 IRI11
IRI17 IRI21 IRI24 IRI27
IRI28 IRI25 IRI3_r IRI13_r
IRI15_r IRI19_r;
%C#2%
IRI6 IRI8 IRI10 IRI11
IRI17 IRI21 IRI24 IRI27
IRI28 IRI25 IRI3_r IRI13_r
IRI15_r IRI19_r;
%C#3%
IRI6 IRI8 IRI10 IRI11
IRI17 IRI21 IRI24 IRI27
IRI28 IRI25 IRI3_r IRI13_r
IRI15_r IRI19_r;
 Bengt O. Muthen posted on Thursday, April 07, 2016 - 9:57 am
You are calling the class variable "class", not c.
 Samuel posted on Monday, February 04, 2019 - 3:01 pm
Dear Drs. Muthen,
I am performing the 3-step procedure with a 5-class LPA and, for now, auxiliary covariates.
My analysis ran properly, but it included a warning:

"TESTS OF CATEGORICAL LATENT VARIABLE MULTINOMIAL LOGISTIC REGRESSIONS USING
THE 3-STEP PROCEDURE

WARNING: LISTWISE DELETION IS APPLIED TO THE AUXILIARY VARIABLES IN THE
ANALYSIS. TO AVOID LISTWISE DELETION, DATA IMPUTATION CAN BE USED
FOR THE AUXILIARY VARIABLES FOLLOWED BY ANALYSIS WITH TYPE=IMPUTATION."

I attempted to add "TYPE = IMPUTATION" to my input syntax, first under "ANALYSIS" and then under "VARIABLE," both of which resulted in error messages. What is the correct syntax for data imputation for the auxiliary variables?
 Tihomir Asparouhov posted on Monday, February 04, 2019 - 4:31 pm
See User's Guide example 11.5 for how to perform the imputation.

The analysis with imputed data is featured in User's Guide example 13.13.
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: