Syntax
ATAN2(X,Y)
Purpose
ATAN2() returns the arc tangents of X and Y. It is similar to calculating the arc tangent of Y/X, except that the signs of the two parameters determine the quadrant in which the result resides.
You can write this function as ATAN(X,Y). For more information, see ATAN.
Examples
obclient> SELECT ATAN(PI(),0);
+--------------------+
| ATAN(PI(),0) |
+--------------------+
| 1.5707963267948966 |
+--------------------+
1 row in set