Mplus Users Guide v6.. - Muthén & Muthén

TITLE, DATA, VARIABLE, And DEFINE CommandsREPETITION = time;where time is the variable that contains information about the time atwhich the variables in the long data set were measured. If the timevariable does not contain consecutive integer values starting at zero, thetime values must be given. For example,REPETITION = time (4 8 16);specifies that the values 4, 8, and 16 are the values of the variable time.The number of values should be equal to the number of variables in theWIDE option and the order of the values should correspond to the orderof the variables.THE DATA TWOPART COMMANDThe DATA TWOPART command is used to create a binary and acontinuous variable from a continuous variable with a floor effect foruse in two-part (semicontinuous) modeling (Olsen & Schafer, 2001).One situation where this occurs is when variables have a preponderanceof zeros.A set of binary and continuous variables are created using the valuespecified in the CUTPOINT option of the DATA TWOPART commandor zero which is the default. The two variables are created using thefollowing rules:1. If the value of the original variable is missing, both the new binaryand the new continuous variable values are missing.2. If the value of the original variable is greater than the cutpoint value,the new binary variable value is one and the new continuous variablevalue is the log of the original variable as the default.3. If the value of the original variable is less than or equal to thecutpoint value, the new binary variable value is zero and the newcontinuous variable value is missing.The new variables must be placed on the USEVARIABLES statement ofthe VARIABLE command if they are used in the analysis. Thesevariables must come after any original variables. If the binary variablesare used as dependent variables in the analysis, they must be declared as469