@property<EOL><INDENT>def _relative_shape_anisotropy(self):<DEDENT>
return calc_relative_shape_anisotropy(<EOL>self.elements, self.coordinates<EOL>)<EOL>
Return relative shape anisotropy of a shape.

The relative shape anisotropy of a shape is weighted by the mass
assigned to each coordinate (associated with the element). In case if
`elements` is `None`, mass of each element = 1 and this returns a
non-weighted value.

Returns
-------
:class:`float`
   The relative shape anisotropy of a shape.