.. ############################################################################
.. manual/packages/vertex-cfd/post_processing.rst
.. ############################################################################

.. _sec_post_processing:

***********************
Post Processing
***********************

`Vertex-CFD` output post-processing utilities can be found under examples/post_processing in the code repository.

Residuals
*********

`residuals.py` is found under the residual folder of post_processing and contains various methods which can be imported into a Python script for easy post-processing of `Vertex-CFD` log files. The module requires the non-standard `numpy`, `pandas`, and `matplotlib` libraries. 

The below code shows an example of reading a Vertex-CFD log file and plotting results. You can use it as a starting point, and test, by copying it to a file in the Vertex-CFD home directory and executing it. You can then modify as needed for your simulation needs.

.. code-block:: python
    
    from pathlib import Path
    import examples.post_processing.residual.residuals as res

    # Reading data
    log_file = Path("examples/post_processing/residual/tests/test_residuals.out")
    info, data = res.get_responses(log_file)
    print(f"The time step's CFL number is: {info['CFL'].iloc[-1]}")
    print(f"The velocity at time step 10 is{data['Velocity-Z Inlet - velocity_2'][10]}")

    # Plotting shortcut functions
    res.plot_residual(log_file)
    res.plot_responses(log_file)