The ATAN2 function returns the arctangent, in radians, of the
quotient of the two arguments.
Upon successful completion, the function returns the arc tangent of
y/x in the range -pi to pi radians, where y
is the first argument and x is the second argument. The specified numbers
must be DOUBLE
PRECISION numbers.
- If either argument is NULL, the result of the function is NULL.
- If the first argument is zero and the second argument is positive, the
result of the function is zero.
- If the first argument is zero and the second argument is negative, the
result of the function is the double value closest to pi.
- If the first argument is positive and the second argument is zero, the
result is the double value closest to pi/2.
- If the first argument is negative and the second argument is zero, the
result is the double value closest to -pi/2.
The data type of the returned value is a DOUBLE PRECISION number.