code: def inverse_transform(self, maps):
          
          sx, sy, sz = self._outputs
          data = coordinates.cartesian_to_spherical(maps[sx], maps[sy], maps[sz])
          out = {param : val for param, val in zip(self._outputs, data)}
          return self.format_output(maps, out)
docs: This function transforms from cartesian to spherical spins.
  
          Parameters
          ----------
          maps : a mapping object
  
          Returns
          -------
          out : dict
              A dict with key as parameter name and value as numpy.array or float
              of transformed values.