%feature("docstring") OT::InverseChiSquare
"InverseChiSquare distribution.

Helper class for defining the Inverse ChiSquare distribution which is the inverse of a :math:`\chi^2` distribution.

Available constructors:
    InverseChiSquare(*nu*)

Parameters
----------
nu : float, :math:`\nu > 0`
    Degrees of freedom.  
    By default, :math:`\nu =1`.
     

Notes
-----
:math:`X` follows an Inverse ChiSquare distribution of parameter :math:`\nu` means that :math:`\dfrac{1}{X}` follows the :math:`\chi^2(\nu)` distribution, with :math:`\nu>0`.
The Inverse ChiSquare distribution parametered by :math:`\nu` is exactly the :math:`InverseGamma(\dfrac{\nu}{2}, 2)` distribution.

Its probability density function is defined as:

.. math::

    f_X(x) = \dfrac{\exp \left( -\dfrac{1}{2 x}\right)}{\Gamma \left(\dfrac{\nu}{2}\right)\lambda^{\frac{\nu}{2}}x^{\frac{\nu}{2}+1}}, \quad x \in [0; +\infty[

with :math:`\nu > 0`.

Its first moments are:

.. math::
    :nowrap:

    \begin{eqnarray*}
        \Expect{X} & = & \dfrac{1}{\nu-2}  \quad \text{if } \nu>2\\
        \Var{X} & = &\dfrac{2}{(\nu-2)^2(\nu-4)}\quad \text{if } \nu>4
    \end{eqnarray*}


Examples
--------
Create a distribution:

>>> import openturns as ot
>>> distribution = ot.InverseChiSquare(1.0)

Draw a sample:

>>> sample = distribution.getSample(5)"

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%feature("docstring") OT::InverseChiSquare::getNu
"Accessor to the  parameter :math:`nu`.

Returns
-------
nu : float
    Degrees of freedom."

// ---------------------------------------------------------------------

%feature("docstring") OT::InverseChiSquare::setNu
"Accessor to the distribution parameter :math:`\nu`.

Parameters
----------
nu : float
    Degrees of freedom."
