Kappa 3 parameter distribution

The probability density function for the Kappa 3 parameter distribution is:

.. math::

f(x, k) = k (k + x^k)^{-(k + 1)/k}

where :math:x > 0 and :math:a > 0.

The following plots show the pdf and cdf:

.. image:: ../../../../tests/imgs/stats/continuous/kappa3/kappa3pdf.png :align: center :width: 480

.. image:: ../../../../tests/imgs/stats/continuous/kappa3/kappa3cdf.png :align: center :width: 480