docs: def dcm2body313(dcm):
      """Convert DCM to body Euler 3-1-3 angles
  
      """
      theta = np.zeros(3)
  
      theta[0] = np.arctan2(dcm[2, 0], dcm[2, 1])
      theta[1] = np.arccos(dcm[2, 2])
      theta[2] = np.arctan2(dcm[0, 2], -dcm[1, 2])
  
      return theta