ATAN2

The ATAN2 function returns the arctan value of the ratio of the input arguments; that is, the angle (in radians) whose tangent is y/x.

Syntax

ATAN (y, x)

Remarks

The table lists the valid input argument data types and the resulting output data types.

Data Type of y and x	Output Type	Notes
BIGINT, DECIMAL, FLOAT, INTEGER, NUMERIC, REAL, SMALLINT, TINYINT	FLOAT	The input ratio y/x can range from -pi/2 to pi/2, inclusive. Output value is in radians.
NULL	NULL

Example

SELECT ATAN2(-5.19615242271, -9);

The result is 0.5773502691 radians, in the third (-x, -y) quadrant.