Mplus Users Guide v6.. - Muthén & Muthén

CHAPTER 15to the number of variables is found. The program then goes to the nextrecord to begin reading information for the next observation. A data setcan contain no more than 500 variables.For data in fixed format, each observation must have the same number ofrecords. Information for a given variable must occupy the same positionon the same record for each observation. A FORTRAN-like formatstatement describing the position of the variables in the data set isrequired. Following is an example of how to specify a format statement:FORMAT IS 5F4.0, 10x, 6F1.0;Although any FORTRAN format descriptor (i.e., F, I, G, E, x, t, /, etc.) isacceptable in a format statement, most format statements use only F, t, x,and /. Following is an explanation of how to create a FORTRAN-likeformat statement using these descriptors.The F format describes the format for a real variable. F is followed by anumber. It can be a whole number or a decimal, for example, F5.3. Thenumber before the decimal point describes the number of columnsreserved for the variable; the number after the decimal point specifiesthe number of decimal places. If the number 34234 is read with an F5.3format, it is read as 34.234. If the data contain a decimal point, it is notnecessary to specify information about the position of the decimal point.For example, the number 34.234 can be read with a F6 format as 34.234.The F format can also be preceded by a number. This number representsthe number of variables to be read using that format. The statement5F5.3 is a shorthand way of saying F5.3, F5.3, F5.3, F5.3, F5.3.There are three options for the format statement related to skippingcolumns or records when reading data: x, t, and /. The x option instructsthe program to skip columns. The statement 10x says to skip 10columns and begin reading in column 11. The t option instructs theprogram to go to a particular column and begin reading. For example,t130 says to go to column 130 and begin reading in column 130. The /option is used to instruct the program to go to the next record. Considerthe following format statements:1. (20F4, 13F5, 3F2)2. (3F4.1,25x,5F5)454