Mplus Users Guide v6.. - Muthén & Muthén

TITLE, DATA, VARIABLE, And DEFINE CommandsUSEOBSERVATIONSThe USEOBSERVATIONS option is used to select observations for ananalysis from the data set named using the FILE option of the DATAcommand. This option is not available for summary data. TheUSEOBSERVATIONS option selects only those observations thatsatisfy the conditional statement specified after the equal sign. Forexample, the following statement selects observations with the variableethnic equal to 1 and the variable gender equal to 2:USEOBSERVATIONS = ethnic EQ 1 AND gender EQ 2;Only variables from the NAMES statement of the VARIABLE commandcan be used in the conditional statement of the USEOBSERVATIONSoption. Logical operators, not arithmetic operators, must be used in theconditional statement. Following are the logical operators that can beused in conditional statements to select observations for analysis:AND logical andOR logical orNOT logical notEQ equal ==NE not equal /=GE greater than or equal to >=LE less than or equal to LT less than