Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 15LONG = y | x;where y and x are two variables that have been measured at multipletime points which are represented by multiple records.WIDEThe WIDE option is used to provide sets of names for the new variablesin the wide format data set. There should be the same number of sets ofnames as there are variables in the LONG statement. The number ofnames in each set corresponds to the number of time points at which thevariables in the long data set were measured. The WIDE option isspecified as follows:WIDE = y1-y4 | x1-x4;where y1, y2, y3, and y4 are the names for the variable y in the wide dataset and x1, x2, x3, and x4 are the names for the variable x in the widedata set.IDVARIABLEThe IDVARIABLE option is used to identify the variable in the longdata set that contains information about the unit to which each recordbelongs. The IDVARIABLE option is specified as follows:IDVARIABLE = subject;where subject is the name of the variable that contains information aboutthe unit to which each record belongs. This variable becomes theidentifier for each observation in the wide data set. The IDVARIABLEoption of the VARIABLE command cannot be used to select a differentidentifier.REPETITIONThe REPETITION option is used to identify the variable that containsinformation about the times at which the variables in the long data setwere measured. The REPETITION option is specified as follows:468