SPSS® 12.0 Command Syntax Reference

Logical Operators
MATRIX—END MATRIX 923
Logical operators combine two matrices, normally containing values of 1 (true) or 0 (false).
When used with other numerical matrices, they treat all positive values as true and all negative
and 0 values as false. The logical operators are:
NOT Reverses the truth of the matrix that follows it. Positive elements yield 0, and negative
or 0 elements yield 1.
AND Both must be true. The matrix A AND B is 1 where the corresponding elements of
A and B are both positive, and 0 elsewhere.
OR Either must be true. The matrix A OR B is 1 where the corresponding element of
either A or B is positive, and 0 where both elements are negative or 0.
XOR Either must be true, but not both. The matrix A XOR B is 1 where one, but not both,
of the corresponding elements of A and B is positive, and 0 where both are positive
or neither is positive.
Precedence of Operators
Parentheses can be used to control the order in which complex expressions are evaluated.
When the order of evaluation is not specified by parentheses, operations are carried out in the
order listed below. The operations higher on the list take precedence over the operations lower
on the list.
+– (Unary)
:
** &**
*&*&/
+– (Addition and Subtraction)
>>=