gcc/fortran/doc/gfortran/intrinsic-procedures/sqrt.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 .. _sqrt:
   7
   8 .. index:: SQRT
   9
  10 .. index:: DSQRT
  11
  12 .. index:: CSQRT
  13
  14 .. index:: ZSQRT
  15
  16 .. index:: CDSQRT
  17
  18 .. index:: root
  19
  20 .. index:: square-root
  21
  22 SQRT --- Square-root function
  23 *****************************
  24
  25 .. function:: SQRT(X)
  26
  27   ``SQRT(X)`` computes the square root of :samp:`{X}`.
  28
  29   :param X:
  30     The type shall be ``REAL`` or
  31     ``COMPLEX``.
  32
  33   :return:
  34     The return value is of type ``REAL`` or ``COMPLEX``.
  35     The kind type parameter is the same as :samp:`{X}`.
  36
  37   Standard:
  38     Fortran 77 and later
  39
  40   Class:
  41     Elemental function
  42
  43   Syntax:
  44     .. code-block:: fortran
  45
  46       RESULT = SQRT(X)
  47
  48   Example:
  49     .. code-block:: fortran
  50
  51       program test_sqrt
  52         real(8) :: x = 2.0_8
  53         complex :: z = (1.0, 2.0)
  54         x = sqrt(x)
  55         z = sqrt(z)
  56       end program test_sqrt
  57
  58   Specific names:
  59     .. list-table::
  60        :header-rows: 1
  61
  62        * - Name
  63          - Argument
  64          - Return type
  65          - Standard
  66
  67        * - ``SQRT(X)``
  68          - ``REAL(4) X``
  69          - ``REAL(4)``
  70          - Fortran 77 and later
  71        * - ``DSQRT(X)``
  72          - ``REAL(8) X``
  73          - ``REAL(8)``
  74          - Fortran 77 and later
  75        * - ``CSQRT(X)``
  76          - ``COMPLEX(4) X``
  77          - ``COMPLEX(4)``
  78          - Fortran 77 and later
  79        * - ``ZSQRT(X)``
  80          - ``COMPLEX(8) X``
  81          - ``COMPLEX(8)``
  82          - GNU extension
  83        * - ``CDSQRT(X)``
  84          - ``COMPLEX(8) X``
  85          - ``COMPLEX(8)``
  86          - GNU extension