gcc/fortran/doc/gfortran/intrinsic-procedures/tanh.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 .. _tanh:
   7
   8 .. index:: TANH
   9
  10 .. index:: DTANH
  11
  12 .. index:: hyperbolic tangent
  13
  14 .. index:: hyperbolic function, tangent
  15
  16 .. index:: tangent, hyperbolic
  17
  18 TANH --- Hyperbolic tangent function
  19 *************************************
  20
  21 .. function:: TANH(X)
  22
  23   ``TANH(X)`` computes the hyperbolic tangent of :samp:`{X}`.
  24
  25   :param X:
  26     The type shall be ``REAL`` or ``COMPLEX``.
  27
  28   :return:
  29     The return value has same type and kind as :samp:`{X}`. If :samp:`{X}` is
  30     complex, the imaginary part of the result is in radians. If :samp:`{X}`
  31     is ``REAL``, the return value lies in the range
  32     - 1 \leq tanh(x) \leq 1 .
  33
  34   Standard:
  35     Fortran 77 and later, for a complex argument Fortran 2008 or later
  36
  37   Class:
  38     Elemental function
  39
  40   Syntax:
  41     .. code-block:: fortran
  42
  43       X = TANH(X)
  44
  45   Example:
  46     .. code-block:: fortran
  47
  48       program test_tanh
  49         real(8) :: x = 2.1_8
  50         x = tanh(x)
  51       end program test_tanh
  52
  53   Specific names:
  54     .. list-table::
  55        :header-rows: 1
  56
  57        * - Name
  58          - Argument
  59          - Return type
  60          - Standard
  61
  62        * - ``TANH(X)``
  63          - ``REAL(4) X``
  64          - ``REAL(4)``
  65          - Fortran 77 and later
  66        * - ``DTANH(X)``
  67          - ``REAL(8) X``
  68          - ``REAL(8)``
  69          - Fortran 77 and later
  70
  71   See also:
  72     :ref:`ATANH`