earthkit.meteo.wind.array.direction
===================================

.. py:function:: earthkit.meteo.wind.array.direction(u, v, convention='meteo', to_positive=True)

   Compute the direction/angle of a vector quantity.

   :param u: u wind/x vector component
   :type u: :class:`array-like`
   :param v: v wind/y vector component (same units as ``u``)
   :type v: :class:`array-like`
   :param convention: Specify how the direction/angle is interpreted. The possible values are as follows:

                      * "meteo": the direction is the meteorological wind direction (see below for explanation)
                      * "polar": the direction is measured anti-clockwise from the x axis (East/right) to the vector
   :type convention: :class:`str`, *optional*
   :param to_positive: If it is True the resulting values are mapped into the [0, 360] range when
                       ``convention`` is "polar". Otherwise they lie in the [-180, 180] range.
   :type to_positive: :class:`bool`, *optional*

   :returns: Direction/angle (degrees)
   :rtype: :class:`array-like`

   The meteorological wind direction is the direction from which the wind is
   blowing. Wind direction increases clockwise such that a northerly wind is 0°, an easterly
   wind is 90°, a southerly wind is 180°, and a westerly wind is 270°. The figure below illustrates
   how it is related to the actual orientation of the wind vector:

   .. image:: /_static/wind_direction.png
       :width: 400px