def poly(self, return_coeffs=False):
        """returns the quadratic as a Polynomial object."""
        p = self.bpoints()
        coeffs = (p[0] - 2*p[1] + p[2], 2*(p[1] - p[0]), p[0])
        if return_coeffs:
            return coeffs
        else:
            return np.poly1d(coeffs)
returns the quadratic as a Polynomial object.