Regularizer
===========

.. toctree::
   :hidden:

   /autoapi/t3toolbox/backend/regularization/Regularizer.value
   /autoapi/t3toolbox/backend/regularization/Regularizer.gradient
   /autoapi/t3toolbox/backend/regularization/Regularizer.hessian
   /autoapi/t3toolbox/backend/regularization/Regularizer.quadratic

.. py:class:: t3toolbox.backend.regularization.Regularizer

   Protocol for a quadratic regularizer ``ρ(X)`` added to the fitting objective.

   A concrete subclass supplies the four contributions the local GN model needs. ``geom`` is a
   :py:class:`t3toolbox.backend.optimizers.GeometryOps`; ``frame`` = ``(U,O,P,Q)``; ``p`` a tangent
   ``(tucker_var, tt_var)``; ``x_cores`` = ``(tucker_cores, tt_cores)``. Tangent-valued methods return a
   gauged/projected tangent.

Methods
-------

.. autoapisummary::

   t3toolbox.backend.regularization.Regularizer.value
   t3toolbox.backend.regularization.Regularizer.gradient
   t3toolbox.backend.regularization.Regularizer.hessian
   t3toolbox.backend.regularization.Regularizer.quadratic