NewtonInfo
==========

.. py:class:: t3toolbox.backend.optimizers.NewtonInfo

   Per-iteration diagnostics passed to a ``newton_cg`` ``callback`` -- everything one Newton step
   produces, so a custom callback (or the display in :py:mod:`t3toolbox.backend.optimizer_display`) can
   report anything without the loop anticipating it. ``x_cores`` (the point *before* the step) and ``lm``
   (its :py:class:`LocalModel` -- residual / sample / frame) are carried so a callback can compute
   per-block errors or evaluate a validation forward. The step-related fields are ``None`` on the final
   **converged** line (no CG / line search ran). The scalar subset (all but ``x_cores`` / ``lm``) is what
   lands in ``stats['history']``.


   .. py:attribute:: iteration
      :type:  int


   .. py:attribute:: objective
      :type:  float


   .. py:attribute:: gnorm
      :type:  float


   .. py:attribute:: g0norm
      :type:  float


   .. py:attribute:: converged
      :type:  bool


   .. py:attribute:: x_cores
      :type:  t3toolbox.backend.common.typ.Any
      :value: None



   .. py:attribute:: lm
      :type:  t3toolbox.backend.common.typ.Any
      :value: None



   .. py:attribute:: misfit
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: regularization
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: forcing_eta
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: cg_tol
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: cg_iters
      :type:  t3toolbox.backend.common.typ.Optional[int]
      :value: None



   .. py:attribute:: cg_maxiter
      :type:  t3toolbox.backend.common.typ.Optional[int]
      :value: None



   .. py:attribute:: cg_resid
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: cg_converged
      :type:  t3toolbox.backend.common.typ.Optional[bool]
      :value: None



   .. py:attribute:: cg_truncated
      :type:  t3toolbox.backend.common.typ.Optional[bool]
      :value: None



   .. py:attribute:: ls_steps
      :type:  t3toolbox.backend.common.typ.Optional[int]
      :value: None



   .. py:attribute:: alpha
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: slope
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: pHp
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: delta_f
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: rho
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: step_rel
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None



   .. py:attribute:: wall_time
      :type:  t3toolbox.backend.common.typ.Optional[float]
      :value: None