.. py:function:: shear_deformation(fx, fy)
*New in Metview version 5.13.0*.
Computes the shear deformation of 2-dimensional vector fields.
:param fx: zonal (west-east) vector component fieldset
:type fx: :class:`Fieldset`
:param fy: meridional (south-north) vector component fieldset
:type fy: :class:`Fieldset`
:rtype: :class:`Fieldset`
The computations for a vector field f=(fx,fy) are based on the following formula:
.. math::
d(f) = \frac{1}{R \ cos\phi}\frac{\partial f_y}{\partial \lambda} + \frac{1}{R}\frac{\partial f_x}{\partial \phi} + \frac{f_x}{R}tan\phi
where:
* R is the radius of the Earth (in m)
* :math:`\phi` is the latitude
* :math:`\lambda` is the longitude.
The derivatives are computed with a second order finite-difference approximation. The resulting fields contain missing values on the poles.
.. warning::
:func:`shear_deformation` is only implemented for regular latitude-longitude grids.
.. note::
See also :func:`stretch_deformation`, :func:`divergence` and :func:`vorticity`.
.. mv-minigallery:: shear_deformation