docs: def asymptotes(hyp, n=1000):
      """
      Gets a cone of asymptotes for hyperbola
      """
      assert N.linalg.norm(hyp.center()) == 0
  
      u = N.linspace(0,2*N.pi,n)
      _ = N.ones(len(u))
      angles = N.array([N.cos(u),N.sin(u),_]).T
      return dot(angles,hyp[:-1,:-1])