Hyperbolic secant distribution

The probability density function for the hyperbolic secant distribution is:

.. math::

f(x) = \frac{1}{\pi} \text{sech}(x)

for a real number :math:x. The following plots show the pdf and cdf:

.. image:: ../../../../tests/imgs/stats/continuous/hypsecant/hypsecantpdf.png :align: center :width: 480

.. image:: ../../../../tests/imgs/stats/continuous/hypsecant/hypsecantcdf.png :align: center :width: 480