Integrators
===========

``cubie.integrators``
---------------------

.. currentmodule:: cubie.integrators

.. toctree::
   :hidden:
   :maxdepth: 2
   :titlesonly:

   single_integrator_run
   integrator_return_codes

The :class:`SingleIntegratorRun` interface is the primary entry point. It creates
a loop callable by combining controller, algorithm, and loop submodules as
directed by the supplied :class:`IntegratorRunSettings`.

The :mod:`cubie.integrators` package coordinates CUDA-based initial value
problem integrations. It bundles algorithm factories, controller builders,
matrix-free solver helpers, and loop orchestrators that combine CUDA device
functions from ODE systems with adaptive or fixed step control.

.. toctree::
   :maxdepth: 2
   :caption: Subpackages
   :titlesonly:

   algorithms
   loops
   matrix_free_solvers
   step_control

Core API
--------

* :doc:`SingleIntegratorRun <single_integrator_run>` – high-level integration driver.
* :doc:`IntegratorReturnCodes <integrator_return_codes>` – enumerates loop exit statuses.


Dependencies
------------

- Implicit algorithms obtain Newton--Krylov helpers from
  :mod:`cubie.integrators.matrix_free_solvers` via ``get_solver_helper_fn``
  closures.
- Loop factories depend on :mod:`cubie.outputhandling` for compile flags and
  saving callbacks generated by
  :class:`cubie.outputhandling.output_functions.OutputFunctions`.
- Controllers operate alongside algorithm step objects exposed by
  :mod:`cubie.integrators.algorithms` to manage adaptive step sizes.