%feature("docstring") OT::GammaMuSigma
"Gamma distribution parameters.

Available constructors:
    GammaMuSigma(*mu=1.0, sigma=1.0, gamma=0.0*)

Parameters
----------
mu : float
    Mean.
sigma : float
    Standard deviation :math:`\sigma > 0`.
gamma : float, optional
    Shift parameter.

Notes
-----
The native parameters are defined as follows:

.. math::

    k &= \left( \frac{\mu-\gamma}{\sigma} \right)^2 \\
    \lambda &= \frac{\mu-\gamma}{\sigma^2}

See also
--------
Gamma

Examples
--------
Create the parameters of the Gamma distribution:

>>> import openturns as ot
>>> parameters = ot.GammaMuSigma(1.5, 2.5, -0.5)

Convert parameters into the native parameters:

>>> print(parameters.evaluate())
[0.64,0.32,-0.5]

The gradient of the transformation of the native parameters into the new
parameters:

>>> print(parameters.gradient())
[[  0.64   0.16   0     ]
 [ -0.512 -0.256  0     ]
 [ -0.64  -0.16   1     ]]"
