UT3Tangent.gauge_residual
=========================

.. py:method:: t3toolbox.uniform_manifold.UT3Tangent.gauge_residual()

   .. code-block:: python

      def gauge_residual(self) -> NDArray:  # shape = variation stack K+C (scalar/0-d when unstacked); cached


   Max absolute gauge-condition violation, **per stack element** (shape = variation stack ``K+C``;
   atol-independent; **cached**). The expensive part of :py:meth:`is_gauged` -- a fixed tangent reused
   across an inner loop (e.g. the safe-mode GAUGE precondition of the manifold inner product) is
   contracted once. See :py:func:`~t3toolbox.backend.utv_operations.utv_gauge_residual`.