Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 13EXAMPLE 13.7: TRANSFORMING VARIABLES USING THEDEFINE COMMANDTITLE:DATA:DEFINE:this is an example of a path analysiswith continuous dependent variables wheretwo variables are transformedFILE IS ex3.11.dat;y1 = y1/100;x3 = SQRT(x3);VARIABLE: NAMES ARE y1-y6 x1-x4;USEVARIABLES = y1-y3 x1-x3;MODEL: y1 y2 ON x1 x2 x3;y3 ON y1 y2 x2;The example above is based on Example 3.11 where the variables arenot transformed. In this example, two variables are transformed usingthe DEFINE command. The variable y1 is transformed by dividing it by100. The variable x3 is transformed by taking the square root of it. Thetransformed variables are used in the estimation of the model. TheDEFINE command can also be used to create new variables.EXAMPLE 13.8: FREEING AND FIXING PARAMETERS ANDGIVING STARTING VALUESTITLE: this is an example of a CFA withcontinuous factor indicators whereparameters are freed, fixed, and startingvalues are givenDATA: FILE IS ex5.1.dat;VARIABLE: NAMES ARE y1-y6;MODEL: f1 BY y1* y2*.5 y3;f2 BY y4* y5 y6*.8;f1-f2@1;The example above is based on Example 5.1 where default startingvalues are used. In this example, parameters are freed, assigned startingvalues, and fixed. In the two BY statements, the factor loadings for y1and y4 are fixed at one as the default because they are the first variablefollowing the BY statement. This is done to set the metric of the factors.To free these parameters, an asterisk (*) is placed after y1 and y4. Thefactor loadings for variables y2, y3, y5, and y6 are free as the default396