UniformGaussNewtonModel.gn_quadratic
====================================

.. py:method:: t3toolbox.fitting.UniformGaussNewtonModel.gn_quadratic(p)

   .. code-block:: python

      def gn_quadratic(self, p: ut3m.UT3Tangent) -> NDArray:  # pᵀHp = ‖J p‖² (+ ⟨p, H_R p⟩), shape C


   The Gauss-Newton quadratic form ``pᵀHp = ‖J p‖²`` -- ONE forward sweep (the Cauchy / line-search
   step-length denominator), not a Hessian apply; plus the regularizer term when set.