netsse.analys.spec.spread_dist_to_spec2d
========================================

.. py:function:: netsse.analys.spec.spread_dist_to_spec2d(Sf, D, theta)

   Converts the given 1-D wave spectrum and directional spreading function
   into a 2-D wave spectrum.

   :param Sf: One-sided variance spectrum of the waves, as a function of
              frequency.
   :type Sf: array_like of shape (...,Nf,...)
   :param D: Directional spreading function.
   :type D: array_like of shape (...,Nf,Ntheta,...)
   :param theta: Vector of wave headings (with arbitrary unit).
   :type theta: array_like of shape (Ntheta,)

   :returns: **S2D** -- Directional wave spectrum, as a function of frequency
             and wave direction (with arbitrary units).
   :rtype: array_like of shape (...,Nf,Ntheta,...)

   .. seealso::

      :py:obj:`spec2d_to_spread_dist`
          Converts the given 2-D wave spectrum into a directional spreading function and a 1-D wave spectrum.

   .. rubric:: Example

   >>> S2D = spread_dist_to_spec2d(Sf,D,theta)