ATAN2

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Returns the arctangent of y/x, using the signs to determine the quadrant.

Signatures

Returns: Arctangent in radians (between -π and π)

ATAN2(y: DOUBLE, x: DOUBLE) → DOUBLE

Notes

• Returns the angle from the positive x-axis to point (x, y)
• Uses signs of both arguments to determine the correct quadrant
• Returns values in the range (-π, π] radians
• ATAN2(0, 1) = 0, ATAN2(1, 0) = π/2, ATAN2(0, -1) = π
• More accurate than ATAN(y/x) for points near axes
• Returns NULL if either input is NULL

Examples

SELECT
    f1 := ATAN2(1.0e0, 1.0e0),  -- 45 degrees (first quadrant)
    f2 := ATAN2(1.0e0, -1.0e0),  -- 135 degrees (second quadrant)
    f3 := ATAN2(-1.0e0, -1.0e0),  -- -135 degrees (third quadrant)
    f4 := ATAN2(-1.0e0, 1.0e0)  -- -45 degrees (fourth quadrant)
;