.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/howto_postprocessing/plot_variables.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_auto_examples_howto_postprocessing_plot_variables.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_examples_howto_postprocessing_plot_variables.py:


Variable presets and data transformation
========================================

.. sectionauthor:: Florian Zill (Helmholtz Centre for Environmental Research GmbH - UFZ)

:py:mod:`ogstools.variables` provides classes (Scalar, Vector, Matrix) which
encapsulate unit handling and data transformation for simplified processing of
mesh data. There are also several predefined variables.

.. GENERATED FROM PYTHON SOURCE LINES 13-18

.. code-block:: Python

    import ogstools as ogs
    from ogstools import examples

    ogs.variables.get_dataframe()






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    <div>
    <style scoped>
        .dataframe tbody tr th:only-of-type {
            vertical-align: middle;
        }

        .dataframe tbody tr th {
            vertical-align: top;
        }

        .dataframe thead th {
            text-align: right;
        }
    </style>
    <table border="1" class="dataframe">
      <thead>
        <tr style="text-align: right;">
          <th></th>
          <th>data_name</th>
          <th>data_unit</th>
          <th>output_unit</th>
          <th>output_name</th>
          <th>type</th>
        </tr>
        <tr>
          <th>preset</th>
          <th></th>
          <th></th>
          <th></th>
          <th></th>
          <th></th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <th>heatflowrate</th>
          <td>HeatFlowRate</td>
          <td></td>
          <td></td>
          <td>HeatFlowRate</td>
          <td>Scalar</td>
        </tr>
        <tr>
          <th>massflowrate</th>
          <td>MassFlowRate</td>
          <td></td>
          <td></td>
          <td>MassFlowRate</td>
          <td>Scalar</td>
        </tr>
        <tr>
          <th>material_id</th>
          <td>MaterialIDs</td>
          <td></td>
          <td></td>
          <td>MaterialIDs</td>
          <td>Scalar</td>
        </tr>
        <tr>
          <th>nodal_forces</th>
          <td>NodalForces</td>
          <td></td>
          <td></td>
          <td>NodalForces</td>
          <td>Vector</td>
        </tr>
        <tr>
          <th>...</th>
          <td>...</td>
          <td>...</td>
          <td>...</td>
          <td>...</td>
          <td>...</td>
        </tr>
        <tr>
          <th>fluid_pressure_crit</th>
          <td>sigma</td>
          <td>Pa</td>
          <td>MPa</td>
          <td>fluid_pressure_criterion</td>
          <td>Scalar</td>
        </tr>
        <tr>
          <th>stress</th>
          <td>sigma</td>
          <td>Pa</td>
          <td>MPa</td>
          <td>stress</td>
          <td>Matrix</td>
        </tr>
        <tr>
          <th>temperature</th>
          <td>temperature</td>
          <td>K</td>
          <td>°C</td>
          <td>temperature</td>
          <td>Scalar</td>
        </tr>
        <tr>
          <th>velocity</th>
          <td>velocity</td>
          <td>m/s</td>
          <td>m/s</td>
          <td>darcy_velocity</td>
          <td>Vector</td>
        </tr>
      </tbody>
    </table>
    <p>18 rows × 5 columns</p>
    </div>
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 19-23

Scalar, Vector and Matrix inherit from the class Variable with its
:meth:`~ogstools.variables.variable.Variable.transform` function.
This function converts the argument from data_unit to output_unit and
applies a function if specified. In this case we convert from K to °C:

.. GENERATED FROM PYTHON SOURCE LINES 25-27

.. code-block:: Python

    ogs.variables.temperature.transform(273.15, strip_unit=False)






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    0.0 °C
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 28-30

You can also create your own variables by creating a Scalar, Vector or Matrix
variable. The following doesn't do any unit conversion.

.. GENERATED FROM PYTHON SOURCE LINES 32-37

.. code-block:: Python

    custom_temperature = ogs.variables.Scalar(
        data_name="temperature", data_unit="K", output_unit="K"
    )
    custom_temperature.transform(273.15, strip_unit=False)






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    273.15 K
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 38-39

Or use existing presets as a template and replace some parameters:

.. GENERATED FROM PYTHON SOURCE LINES 39-42

.. code-block:: Python

    custom_temperature = ogs.variables.temperature.replace(output_unit="°F")
    custom_temperature.transform(273.15, strip_unit=False)






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    31.999999999999936 °F
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 43-48

Components of Vector variables and Matrix variables can be accessed with
bracket indexing. :class:`~ogstools.variables.vector.Vector` variables
should be of length 2 or 3 corresponding to the dimension.
:class:`~ogstools.variables.matrix.Matrix` variables likewise should be of
length 4 [xx, yy, zz, xy] or 6 [xx, yy, zz, xy, yz, xz].

.. GENERATED FROM PYTHON SOURCE LINES 50-52

.. code-block:: Python

    ogs.variables.displacement[1].transform([0.01, 0.02, 0.03], strip_unit=False)






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    0.02 m
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 53-57

.. code-block:: Python

    ogs.variables.strain["xx"].transform(
        [0.01, 0.02, 0.03, 0.04, 0.05, 0.06], strip_unit=False
    )






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    1.0 %
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 58-59

Magnitude of a 2D displacement vector:

.. GENERATED FROM PYTHON SOURCE LINES 61-63

.. code-block:: Python

    ogs.variables.displacement.magnitude.transform([0.03, 0.04], strip_unit=False)






.. raw:: html

    <div class="output_subarea output_html rendered_html output_result">
    0.05 m
    </div>
    <br />
    <br />

.. GENERATED FROM PYTHON SOURCE LINES 64-68

We suggest specifying the variables and their transformations once.
These can be reused in different kind of post processing. When plotting
with :py:mod:`ogstools.plot` we can use these presets to simplify the
task of processing the data (e.g. calculate the von Mises stress):

.. GENERATED FROM PYTHON SOURCE LINES 70-74

.. code-block:: Python

    fig = ogs.plot.contourf(
        examples.load_mesh_mechanics_2D(), ogs.variables.stress.von_Mises
    )




.. image-sg:: /auto_examples/howto_postprocessing/images/sphx_glr_plot_variables_001.png
   :alt: plot variables
   :srcset: /auto_examples/howto_postprocessing/images/sphx_glr_plot_variables_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 75-77

Have a look at
:ref:`sphx_glr_auto_examples_howto_plot` for more examples.


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.254 seconds)


.. _sphx_glr_download_auto_examples_howto_postprocessing_plot_variables.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_variables.ipynb <plot_variables.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_variables.py <plot_variables.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_variables.zip <plot_variables.zip>`