code: def _get_lattice_parameters(lattice):
      
  
      return np.array(np.sqrt(np.dot(lattice.T, lattice).diagonal()),
                      dtype='double')
docs: Return basis vector lengths
  
      Parameters
      ----------
      lattice : array_like
          Basis vectors given as column vectors
          shape=(3, 3), dtype='double'
  
      Returns
      -------
      ndarray, shape=(3,), dtype='double'