Domain errors

Domain errors occur when numeric expressions are mathematically undefined or cannot be represented numerically on the computer for reasons other than missing data. Two common examples are division by 0 and the square root of a negative number. When there is a domain error, a warning is issued, and the system-missing value is assigned to the expression. For example, the command COMPUTE TESTVAR = TRUNC(SQRT(X/Y) * .5) returns system-missing if X/Y is negative or if Y is 0.

The following are domain errors in numeric expressions:

**. A negative number to a noninteger power.

/. A divisor of 0.

MOD. A divisor of 0.

SQRT . A negative argument.

EXP. An argument that produces a result too large to be represented on the computer.

LG10. A negative or 0 argument.

LN. A negative or 0 argument.

ARSIN. An argument whose absolute value exceeds 1.

NORMAL. A negative or 0 argument.

PROBIT. A negative or 0 argument, or an argument 1 or greater.