# ATAN2D

Elemental Intrinsic Function (Generic): Produces an arctangent. The result is the principal value of the argument of the nonzero complex number (x, y).

result = ATAN2D (y,x)

y | (Input) Must be of type real.
x | (Input) Must have the same type and kind parameters as y. If y has the value zero, x cannot have the value zero.

## Results

The result type and kind are the same as x and are expressed in degrees. The value lies in the range -180 degrees to 180 degrees. If x zero, the result is approximately equal to the value of arctan (y/ x).

If y > zero, the result is positive.

If y < zero, the result is negative.

If y = zero, the result is zero (if x > zero) or 180 degrees (if x < zero).

If x = zero, the absolute value of the result is 90 degrees.

Specific Name | Argument Type | Result Type
--- | --- | ---
ATAN2D | REAL(4) | REAL(4)
DATAN2D | REAL(8) | REAL(8)
QATAN2D | REAL(16) | REAL(16)

## Example

ATAN2D (2.679676, 1.0) has the value 69.53546.

Parent topic: A to B