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Hi! I am hoping to get some help with this. I would like to create a product term in MPlus via the syntax as opposed to having to do this through spss first. The questions I have are: 1. How can I center a given variable around the mean? What is the command for this? In spss the centered variable will take a new name. How will I do this in MPlus? 2. Once I mean center the variable how can I then create the product term? Will I use DEFINE and incorporate #1 into it? I would like to learn these commands. I would appreciate your help with this by letting me know the actual commands. Thanks in advance. 


See the CENTERING option of the VARIABLE command. You need to save the centered variables and then create the interaction using DEFINE in a second step. 

tes1800 posted on Wednesday, January 25, 2012  3:09 pm



Hi, I used the technique you mention above to center some observed variables that I hope to use to compute a crossproduct interaction term. I created several composite variables using the DEFINE statement, and then centered some of these. I used the SAVEDATA command to save all the variables I created in the DEFINE command as well as several additional variables that I included with the AUXILIARY command. I used this new data file as input for some additional analyses, and I received an error message as follows: *** ERROR Invalid symbol in data file: "1.000*" at record #: 5, field #: 3 In the manual, I see that the SAVEDATA command uses * for missing values, but how do I address this when pulling my new saved file to use in new analyses? Thank you! 


You use the statement MISSING = *; 

tes1800 posted on Wednesday, January 25, 2012  3:22 pm



Hmmm...still getting the same error message. Any other issues that might be driving that error message? 


Perhaps you need to specify the fixed format that shows in the output of your first run (at the end)  putting that into the DATA command of your second run. 

tes1800 posted on Wednesday, January 25, 2012  6:28 pm



That worked! Thank you so much for your speedy response! 


Hi, I want to use the centred variables I computed in SPSS for my data analysis in MPlus. Within those centred variables some of the variables are signed minus. MPlus respond on those signs with this error message: *** ERROR Invalid symbol in data file: "" at record #: 2, field #: 21 Is there any way I can use the centred variables I computed in SPSS? Thank you in advance! 


Variables can have minus signs. Please send the output, data, and your license number to support@statmodel.com. 


Thank you a lot for the fast answer. The message doesn't appear if I change the decimal delimiter in spss from comma to point. but the scales in my .dat document seem to be shifted. Now there is a convergance problem (NO CONVERGENCE. NUMBER OF ITERATIONS EXCEEDED.). I increased the number of iteration to 10000 and I tried different start values. I rescaled the continuous variables with large variance by dividing them by a constant, but the convergence problem still appears. If I leave out the minus signs there is no problem of convergence at all. Could the problem be connected to the shifted scales? How can I transfer my data from SPSS to ACII without any shifting effects on my scales? Thank you in advance! 


I can't answer your question without the information I requested. 

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