solver_callback (2D)
''''''''''''''''''''

:Sources:

.. collapse:: solver_callback.py (click to expand)

.. literalinclude:: examples/python/solid_mechanics_model/solver_callback/solver_callback.py
:language: python
:lines: 9-

.. collapse:: material.dat (click to expand)

.. literalinclude:: examples/python/solid_mechanics_model/solver_callback/material.dat
:language: text

:Location:

``examples/python/solid_mechanics_model/`` `solver_callback <https://gitlab.com/akantu/akantu/-/blob/master/examples/python/solid_mechanics_model/solver_callback/>`_


In ``solver_callback``, it is shown how to write a solver callback function. It is done by writing a class that inherit
from ``InterceptSolverCallback``::

class SolverCallback(aka.InterceptSolverCallback):
[.....]

solver_callback = SolverCallback(model)

model.solveStep(solver_callback)

In that case, the solver callback is used to modify the stiffness matrix.