docs: def convert_radian(coord, *variables):
      """Convert the given coordinate from radian to degree
  
      Parameters
      ----------
      coord: xr.Variable
          The variable to transform
      ``*variables``
          The variables that are on the same unit.
  
      Returns
      -------
      xr.Variable
          The transformed variable if one of the given `variables` has units in
          radian"""
      if any(v.attrs.get('units') == 'radian' for v in variables):
          return coord * 180. / np.pi
      return coord