gcc/fortran/doc/gfortran/intrinsic-procedures/exp.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 .. _exp:
   7
   8 .. index:: EXP
   9
  10 .. index:: DEXP
  11
  12 .. index:: CEXP
  13
  14 .. index:: ZEXP
  15
  16 .. index:: CDEXP
  17
  18 .. index:: exponential function
  19
  20 .. index:: logarithm function, inverse
  21
  22 EXP --- Exponential function
  23 *****************************
  24
  25 .. function:: EXP(X)
  26
  27   ``EXP(X)`` computes the base e exponential of :samp:`{X}`.
  28
  29   :param X:
  30     The type shall be ``REAL`` or
  31     ``COMPLEX``.
  32
  33   :return:
  34     The return value has same type and kind as :samp:`{X}`.
  35
  36   Standard:
  37     Fortran 77 and later, has overloads that are GNU extensions
  38
  39   Class:
  40     Elemental function
  41
  42   Syntax:
  43     .. code-block:: fortran
  44
  45       RESULT = EXP(X)
  46
  47   Example:
  48     .. code-block:: fortran
  49
  50       program test_exp
  51         real :: x = 1.0
  52         x = exp(x)
  53       end program test_exp
  54
  55   Specific names:
  56     .. list-table::
  57        :header-rows: 1
  58
  59        * - Name
  60          - Argument
  61          - Return type
  62          - Standard
  63
  64        * - ``EXP(X)``
  65          - ``REAL(4) X``
  66          - ``REAL(4)``
  67          - Fortran 77 and later
  68        * - ``DEXP(X)``
  69          - ``REAL(8) X``
  70          - ``REAL(8)``
  71          - Fortran 77 and later
  72        * - ``CEXP(X)``
  73          - ``COMPLEX(4) X``
  74          - ``COMPLEX(4)``
  75          - Fortran 77 and later
  76        * - ``ZEXP(X)``
  77          - ``COMPLEX(8) X``
  78          - ``COMPLEX(8)``
  79          - GNU extension
  80        * - ``CDEXP(X)``
  81          - ``COMPLEX(8) X``
  82          - ``COMPLEX(8)``
  83          - GNU extension