gcc/fortran/doc/gfortran/intrinsic-procedures/atanh.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 .. _atanh:
   7
   8 .. index:: ATANH
   9
  10 .. index:: DATANH
  11
  12 .. index:: area hyperbolic tangent
  13
  14 .. index:: inverse hyperbolic tangent
  15
  16 .. index:: hyperbolic function, tangent, inverse
  17
  18 .. index:: tangent, hyperbolic, inverse
  19
  20 ATANH --- Inverse hyperbolic tangent function
  21 *********************************************
  22
  23 .. function:: ATANH(X)
  24
  25   ``ATANH(X)`` computes the inverse hyperbolic tangent of :samp:`{X}`.
  26
  27   :param X:
  28     The type shall be ``REAL`` or ``COMPLEX``.
  29
  30   :return:
  31     The return value has same type and kind as :samp:`{X}`. If :samp:`{X}` is
  32     complex, the imaginary part of the result is in radians and lies between
  33     -\pi/2 \leq \Im \atanh(x) \leq \pi/2.
  34
  35   Standard:
  36     Fortran 2008 and later
  37
  38   Class:
  39     Elemental function
  40
  41   Syntax:
  42     .. code-block:: fortran
  43
  44       RESULT = ATANH(X)
  45
  46   Example:
  47     .. code-block:: fortran
  48
  49       PROGRAM test_atanh
  50         REAL, DIMENSION(3) :: x = (/ -1.0, 0.0, 1.0 /)
  51         WRITE (*,*) ATANH(x)
  52       END PROGRAM
  53
  54   Specific names:
  55     .. list-table::
  56        :header-rows: 1
  57
  58        * - Name
  59          - Argument
  60          - Return type
  61          - Standard
  62
  63        * - ``DATANH(X)``
  64          - ``REAL(8) X``
  65          - ``REAL(8)``
  66          - GNU extension
  67
  68   See also:
  69     Inverse function:
  70     :ref:`TANH`