ATAN2
Description
The ATAN2 function is used to calculate the arctangent value of two floating-point numbers y and x, with the return value in radians. Unlike the ATAN function, ATAN2 can handle cases where x is zero or y and x have opposite signs, thus obtaining the correct quadrant result.
Parameter Description
y (double type): The floating-point value of the y-axis coordinate.x (double type): The floating-point value of the x-axis coordinate.
Return Result
Returns the arctangent value of y/x, with the type being double.
Usage Example
-- Example 1
SELECT ATAN2(0, 0); -- The result is 0.0 because the intersection of the two axes is at the origin
-- Example 2
SELECT ATAN2(1, 1); -- The result is approximately 0.7853981633974483, which is 45°, indicating the angle in the first quadrant
-- Example 3
SELECT ATAN2(-1, 1); -- The result is approximately -0.7853981633974483, which is -45°, indicating the angle in the second quadrant
-- Example 4
SELECT ATAN2(1, -1); -- The result is approximately 2.356194490192345, which is 135°, indicating the angle in the second quadrant
-- Example 5
SELECT ATAN2(-1, -1); -- The result is approximately -2.356194490192345, which is 180°, indicating the angle in the third quadrant
-- Example 6
SELECT ATAN2(1, 0); -- The result is approximately 1.570796326794896
-- Example 7
SELECT ATAN2(0, 1); -- The result is approximately 0.0 because y/x is on the y-axis
-- Example 8
SELECT ATAN2(0, -1); -- The result is approximately 3.141592653589793
