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ATAN2

Calculate arc tangent of two variables. This function returns the angle in radians between the positive x-axis and the point (X, Y).

Syntax

ATAN(Y,X), ATAN2(Y,X)

Description

Returns the arc tangent of the two variables X and Y. It is similar to calculating the arc tangent of Y / X, except that the signs of both arguments are used to determine the quadrant of the result.

Examples

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SELECT ATAN(-2,2);
+---------------------+
| ATAN(-2,2)          |
+---------------------+
| -0.7853981633974483 |
+---------------------+

SELECT ATAN2(PI(),0);
+--------------------+
| ATAN2(PI(),0)      |
+--------------------+
| 1.5707963267948966 |
+--------------------+