Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 15THE DATA COMMANDThe DATA command is used to provide information about the data setto be analyzed. The DATA command has options for specifying thelocation of the data set to be analyzed, describing the format and type ofdata in the data set, specifying the number of observations and numberof groups in the data set if the data are in summary form such as acorrelation or covariance matrix, requesting listwise deletion ofobservations with missing data, and specifying whether the data shouldbe checked for variances of zero.Data must be numeric except for certain missing value flags and mustreside in an external ASCII file. A data set can contain no more than500 variables. The maximum record length is 5000. Special features ofthe DATA command for multiple group analysis are discussed in 14.Monte Carlo data generation is discussed in Chapters 12 and 19. Theestimator chosen for an analysis determines the type of data required forthe analysis. Some estimators require a data set with information foreach observation. Some estimators require only summary information.There are six DATA transformation commands. They are used torearrange data from a wide to long format, to rearrange data from a longto wide format, to create a binary and a continuous variable from asemicontinuous variable, to create a set of binary variables that areindicators of missing data, to create variables for discrete-time survivalmodeling, and to rearrange longitudinal data from a format where timepoints represent measurement occasions to a format where time pointsrepresent age or another time-related variable.450