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 - 9:09 pm
I used the technique you mention above to center some observed variables that I hope to use to compute a cross-product 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?
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 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?