ATAND (The GNU Fortran Compiler)

### 8.29 `ATAND` — Arctangent function, degrees ¶

Synopsis:

  `RESULT = ATAND(X)`
  `RESULT = ATAND(Y, X)`

Description:

  `ATAND(X)` computes the arctangent of X in degrees (inverse of `TAND` — Tangent function, degrees).

Class:

  Elemental function

Arguments:

  X | The type shall be `REAL`.
  Y | The type and kind type parameter shall be the same as X.

Return value:

  The return value is of the same type and kind as X. If Y is present, the result is identical to `ATAN2D(Y, X)`. Otherwise, the result is in degrees and lies in the range -90 \leq \atand(x) \leq 90.

Example:

      program test_atand
        real(8) :: x = 2.866_8
        real(4) :: x1 = 1.e0_4, y1 = 0.5e0_4
        x = atand(x)
        x1 = atand(y1, x1)
      end program test_atand

Specific names:

  Name | Argument | Return type | Standard
  --- | --- | --- | ---
  `ATAND(X)` | `REAL(4) X` | `REAL(4)` | Fortran 2023
  `DATAND(X)` | `REAL(8) X` | `REAL(8)` | GNU extension

Standard:

  Fortran 2023

See also:

  Inverse function:
  `TAND` — Tangent function, degrees
  Radians function:
  `ATAN` — Arctangent function