var_a.rst

var_a

.. py:function:: var_a(fs, [area])

   Computes the area weighted variance for each field in ``fs``.

   :param fs: input fieldset
   :type fs: :class:`Fieldset`
   :param list area: area as [N,W,S,E] to perform the computations
   :rtype: number or list

   If the ``area`` is not specified the whole field will be used in the calculation. The result is a number for a single field or a list for a multi-field :class:`Fieldset`.

   .. note::

      The computations are implemented via :func:`integrate` and the following lines are equivalent:

      .. code-block:: python

         y = mv.var_a(x)
         y = mv.integrate(x*x) - mv.integrate(x)**2

   .. note::

        See also :func:`integrate`, :func:`var`, :func:`rms_a` and :func:`stdev_a`.

.. mv-minigallery:: var_a