ATAN

Description

Returns the arctangent of x, where x is in radians.

Syntax

ATAN(<x>)

Parameters

Parameter	Description
<x>	The value for which the atan value is to be calculated

Return Value

The atan value of parameter x.

Special Cases

• When x is NaN, returns NaN
• When x is positive infinity, returns π/2 (approximately 1.570796326794897)
• When x is negative infinity, returns -π/2 (approximately -1.570796326794897)
• When x is NULL, returns NULL

Examples

select atan(0);

+-----------+
| atan(0.0) |
+-----------+
|         0 |
+-----------+

select atan(2);

+--------------------+
| atan(2.0)          |
+--------------------+
| 1.1071487177940904 |
+--------------------+

select atan(cast('nan' as double));

+-----------------------------+
| atan(cast('nan' AS DOUBLE)) |
+-----------------------------+
| NaN                         |
+-----------------------------+

select atan(cast('inf' as double));

+-----------------------------+
| atan(cast('inf' AS DOUBLE)) |
+-----------------------------+
| 1.570796326794897           |
+-----------------------------+

select atan(cast('-inf' as double));

+------------------------------+
| atan(cast('-inf' AS DOUBLE)) |
+------------------------------+
| -1.570796326794897           |
+------------------------------+