CONAN.utils.impact_parameter
============================

.. py:function:: CONAN.utils.impact_parameter(inc, a, e=0, w=90, tra_occ='tra')

   Function to convert inclination in degrees to  impact parameter b.

   :param inc:
   :type inc: Inclination in degrees.
   :param a:
   :type a: Scaled semi-major axis i.e. a/R*.
   :param e: eccentricity of the orbit.
   :type e: float;
   :param w: longitude of periastron in degrees
   :type w: float;

   :returns: *
             * **b** (*the impact parameter*)