ATAN2 function
ATAN2 is a trigonometric function that returns the arc tangent of one number
divided by another number. The return value is in radians and is between PI/2
and PI/2
.
Syntax
ATAN2(number1, number2)
Arguments
 number1

A
DOUBLE PRECISION
number.  number2

A
DOUBLE PRECISION
number.
Return type
DOUBLE PRECISION
Examples
To return the arc tangent of 2/2
and multiply it by 4, use the following example.
SELECT ATAN2(2,2) * 4 AS PI;
++  pi  ++  3.141592653589793  ++
To convert the arc tangent of 1/0
(which evaluates to 0) to the equivalent
number of degrees, use the following example.
SELECT (ATAN2(1,0) * 180/(SELECT PI())) AS degrees;
++  degrees  ++  90  ++