SPSS® 12.0 Command Syntax Reference

Example
LEAVE 797
• Numeric variables named on LEAVE are initialized to 0 for the first case, and string variables
are initialized to blanks. These variables are not reinitialized when new cases are
read.
COMPUTE TSALARY=TSALARY+SALARY.
LEAVE TSALARY.
FORMAT TSALARY (DOLLAR8)/ SALARY (DOLLAR7).
• These commands keep a running total of salaries across all cases. SALARY is the variable
containing the employee’s salary, and TSALARY is the new variable containing the
cumulative salaries for all previous cases.
• For the first case, TSALARY is initialized to 0, and TSALARY equals SALARY. For the rest
of the cases, TSALARY stores the cumulative totals for SALARY.
• LEAVE follows COMPUTE because TSALARY must first be defined before it can be specified
on LEAVE.
• If LEAVE were not specified for this computation, TSALARY would be initialized to systemmissing
for all cases. TSALARY would remain system-missing because its value would be
missing for every computation.
Example
SORT CASES DEPT.
IF DEPT NE LAG(DEPT,1) TSALARY=0. /*Initialize for new dept
COMPUTE TSALARY=TSALARY+SALARY. /*Sum salaries
LEAVE TSALARY. /*Prevent initialization
each case
FORMAT TSALARY (DOLLAR8)/ SALARY (DOLLAR7).
• These commands accumulate a sum across cases for each department.
• SORT first sorts cases by the values of variable DEPT.
• IF specifies that if the value of DEPT for the current case is not equal to the value of DEPT
for the previous case, TSALARY equals 0. Thus, TSALARY is reset to 0 each time the value
of DEPT changes. (For the first case in the file, the logical expression on IF is missing.
However, the desired effect is obtained because LEAVE initializes TSALARY to 0 for the
first case, independent of the IF statement.)
• LEAVE prevents TSALARY from being initialized for cases within the same department.