gamma
==============================================

Purpose
----------------

Returns the value of the gamma function.

Format
----------------
.. function:: g = gamma(x)

    :param x: the values used to evaluate the gamma function.
    :type x: NxK matrix or N-dimensional array

    :return g: the value of the gamma function evaluated at *x*.

    :rtype g: NxK matrix or N-dimensional array

Examples
----------------

::

    g = gamma(2.5);

After the code above:

::

    g = 1.329340

Remarks
-------

For each element of *x* this function returns the integral

.. math::

   \int_{0}^{\infty}t^{(x−1)⁢}e^{−t}dt

All elements of *x* must be positive and less than or equal to 169. Values
of *x* greater than 169 will cause an overflow.

The natural log of :func:`gamma` is often what is required and it can be
computed without the overflow problems of :func:`gamma` using :func:`lnfact`.


.. seealso:: Functions :func:`cdfchic`, :func:`cdfbeta`, :func:`cdffc`, :func:`cdfnc`, :func:`cdftc`, :func:`erf`, :func:`erfc`, :func:`lnfact`