8.2.3 ATAN

Returns the angle (in radians) that is the inverse tangent of the target data, in the range - [Figure] /2 to /2.

Organization of this subsection

(1) Specification format

scalar-function-ATAN ::= ATAN(target-data)
 
  target-data ::= value-expression

target-data:

Specifies the numeric data whose inverse tangent is to be determined.

The following rules apply:

Specify the target data in the form of a value expression. For details about value expressions, see 7.20 Value expression.
Specify numeric data for the target data. For details about numeric data, see (1) Numeric data in 6.2.1 List of data types.
You cannot specify a dynamic parameter by itself for the target data.

The data type of the execution result is the DOUBLE PRECISION type.
The NOT NULL constraint does not apply to the value of the execution result (the null value is allowed).
If the target data has the null value, the execution result will be a null value.

Example:

Determine the inverse tangent of the values in columns C1 to C3 in table T1.

SELECT ATAN("C1"),ATAN("C2"),ATAN("C3") FROM "T1"

[Figure]