.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "examples/plot_03_volume_sampling.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_examples_plot_03_volume_sampling.py>`
        to download the full example code.

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

.. _sphx_glr_examples_plot_03_volume_sampling.py:


.. _random_volume_sampling_example:

Random Sampling in a Volume
~~~~~~~~~~~~~~~~~~~~~~~~~~~

This example inspired by the discussion in
`this PyVista discussion <https://github.com/pyvista/pyvista/discussions/2703#discussioncomment-2828140>`_.
Using ``pyransame`` makes the solution easier and handles more complex scenarios.
This example is related to post-processing CFD data with a Eulerian description
of particle density.

.. GENERATED FROM PYTHON SOURCE LINES 13-19

.. code-block:: Python


    import numpy as np
    import pyvista as pv

    import pyransame








.. GENERATED FROM PYTHON SOURCE LINES 20-26

This example shows how ``pyransame`` can be used to sampled from datasets
that have volume. There is a cube of dimension 10 m x 10 m x 10 m
with particles described by a volume fraction in each cell.
In this synthetic dataset, the
particles tend to float and are located near the top (z-position).
``cell_centers`` is used as cell_data is required for weighted sampling.

.. GENERATED FROM PYTHON SOURCE LINES 26-31

.. code-block:: Python


    mesh = pv.ImageData(dimensions=(10, 10, 10))
    mesh.cell_data["volume_frac"] = np.exp(mesh.cell_centers().points[:, 2])
    mesh.cell_data["volume_frac"] /= np.sum(mesh["volume_frac"])








.. GENERATED FROM PYTHON SOURCE LINES 32-35

The particles have an age related to some history of the particle motion, in
this case related to the y-position.  Cell data is not required here as
the point data can be interpolated onto the sampled points.

.. GENERATED FROM PYTHON SOURCE LINES 35-38

.. code-block:: Python


    mesh["age"] = mesh.points[:, 1]








.. GENERATED FROM PYTHON SOURCE LINES 39-41

Sample the points with respect to the volume fraction to obtain a realistic
particle distribution in the domain.

.. GENERATED FROM PYTHON SOURCE LINES 41-44

.. code-block:: Python


    points = pyransame.random_volume_dataset(mesh, 1000, weights="volume_frac")








.. GENERATED FROM PYTHON SOURCE LINES 45-47

In this example, we also know the particles diameters come from a normal
distribution that does not depend on the other particle attributes.

.. GENERATED FROM PYTHON SOURCE LINES 47-51

.. code-block:: Python


    diameters = 0.03 * np.random.randn(1000) + 0.4
    points["diameter"] = diameters








.. GENERATED FROM PYTHON SOURCE LINES 52-53

Plot.

.. GENERATED FROM PYTHON SOURCE LINES 53-59

.. code-block:: Python

    cpos = [[32.0, 16.0, 10.0], [5.0, 3.9, 3.6], [-0.21, -0.076, 0.97]]
    pl = pv.Plotter()
    pl.add_mesh(mesh, style="wireframe")
    spheres = points.glyph(geom=pv.Sphere(), scale="diameter", orient=False)
    pl.add_mesh(spheres, scalars="age")
    pl.show()







.. tab-set::



   .. tab-item:: Static Scene



            
     .. image-sg:: /examples/images/sphx_glr_plot_03_volume_sampling_001.png
        :alt: plot 03 volume sampling
        :srcset: /examples/images/sphx_glr_plot_03_volume_sampling_001.png
        :class: sphx-glr-single-img
     


   .. tab-item:: Interactive Scene



       .. offlineviewer:: /home/runner/work/pyransame/pyransame/doc/examples/images/sphx_glr_plot_03_volume_sampling_001.vtksz







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

   **Total running time of the script:** (0 minutes 7.930 seconds)


.. _sphx_glr_download_examples_plot_03_volume_sampling.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: plot_03_volume_sampling.ipynb <plot_03_volume_sampling.ipynb>`

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

      :download:`Download Python source code: plot_03_volume_sampling.py <plot_03_volume_sampling.py>`


.. only:: html

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

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