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

.. only:: html

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

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

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

.. _sphx_glr_auto_how_to_example_sample_plane.py:


Sample a field on a cutting plane
=================================

Interpolating a volume field onto a plane is the 2-D analogue of
:doc:`example_sample_line`. You get back a ``SurfaceDataSet`` — face
centres, face areas, and the sampled field. From there the usual reducers
apply (``Mean``, ``Sum``, ``SurfIntegrate``).

.. GENERATED FROM PYTHON SOURCE LINES 12-14

Open the case
-------------

.. GENERATED FROM PYTHON SOURCE LINES 14-37

.. code-block:: Python


    import os
    import subprocess

    import pyOFTools.patch_pybfoam  # noqa: F401
    from pyOFTools import clone_example

    CASE = clone_example("damBreak")
    subprocess.run(
        ["./Allrun"],
        cwd=CASE,
        check=True,
        env={**os.environ},
        capture_output=True,
        text=True,
    )

    from pybFoam import Time, fvMesh, volScalarField

    time = Time(str(CASE.parent), CASE.name)
    mesh = fvMesh(time)
    volScalarField.read_field(mesh, "p")





.. rst-class:: sphx-glr-script-out

 .. code-block:: none


    <pybFoam.pybFoam_core.volScalarField object at 0x7f46deccb790>



.. GENERATED FROM PYTHON SOURCE LINES 38-42

Sample p on a mid-plane
-----------------------
``plane`` gives the geometry; ``sample(mesh, "p")`` interpolates ``p``
onto it.

.. GENERATED FROM PYTHON SOURCE LINES 42-56

.. code-block:: Python


    from pyOFTools.aggregators import Max, Mean
    from pyOFTools.builders import plane, sample

    mid_plane_mean = (
        plane(mesh, point=(0.0, 0.292, 0.0), normal=(0, 1, 0)) | sample(mesh, "p") | Mean()
    ).compute()
    print(f"mean p on y=0.292 plane = {mid_plane_mean.values[0].value:.4g} Pa")

    mid_plane_max = (
        plane(mesh, point=(0.0, 0.292, 0.0), normal=(0, 1, 0)) | sample(mesh, "p") | Max()
    ).compute()
    print(f"max  p on y=0.292 plane = {mid_plane_max.values[0].value:.4g} Pa")





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    mean p on y=0.292 plane = 1e+05 Pa
    max  p on y=0.292 plane = 1e+05 Pa




.. GENERATED FROM PYTHON SOURCE LINES 57-62

Scatter plot of sampled values
------------------------------
To inspect the field itself (not a reduction), ``compute()`` the plane
workflow after ``sample`` but without a reducer — the returned object is
the ``SurfaceDataSet`` with geometry and field populated.

.. GENERATED FROM PYTHON SOURCE LINES 62-83

.. code-block:: Python


    from pyOFTools.workflow import WorkFlow

    plane_wf = plane(mesh, point=(0.0, 0.292, 0.0), normal=(0, 1, 0)) | sample(mesh, "p")
    assert isinstance(plane_wf, WorkFlow)
    surface_ds = plane_wf.compute()

    import matplotlib.pyplot as plt
    import numpy as np

    positions = np.asarray(surface_ds.geometry.positions)
    p_values = np.asarray(surface_ds.field)

    fig, ax = plt.subplots(figsize=(6, 4))
    sc = ax.scatter(positions[:, 0], positions[:, 2], c=p_values, s=6)
    ax.set_xlabel("x [m]")
    ax.set_ylabel("z [m]")
    ax.set_title("p on y=0.292 plane")
    fig.colorbar(sc, ax=ax, label="p [Pa]")
    fig.tight_layout()
    plt.show()



.. image-sg:: /auto_how_to/images/sphx_glr_example_sample_plane_001.png
   :alt: p on y=0.292 plane
   :srcset: /auto_how_to/images/sphx_glr_example_sample_plane_001.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 10.599 seconds)


.. _sphx_glr_download_auto_how_to_example_sample_plane.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_