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

.. only:: html

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

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

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

.. _sphx_glr_example_gallery_auto_examples_basic_create_tensor_mesh.py:


Create a TensorMesh from a PyVista mesh
=======================================

This tutorial shows the first step in most ``graphlow`` workflows:
build a small PyVista volume mesh, convert it to ``TensorMesh``, and inspect
the basic mesh information exposed by the geometry/topology wrappers.

.. GENERATED FROM PYTHON SOURCE LINES 11-13

Imports
-------

.. GENERATED FROM PYTHON SOURCE LINES 13-19

.. code-block:: Python

    import numpy as np
    import pyvista as pv

    import graphlow









.. GENERATED FROM PYTHON SOURCE LINES 20-24

Step 1: Build a small volume mesh
---------------------------------
Keep the same mesh family across the beginner tutorials so the API changes
are easier to see than the input data changes.

.. GENERATED FROM PYTHON SOURCE LINES 24-35

.. code-block:: Python

    def make_volume_grid() -> pv.UnstructuredGrid:
        """Create a small warped hexahedral grid."""
        x = np.array([0.0, 1.0, 2.2, 3.5], dtype=np.float32)
        y = np.array([0.0, 0.8, 1.7], dtype=np.float32)
        z = np.array([0.0, 0.6, 1.4], dtype=np.float32)
        X, Y, Z = np.meshgrid(x, y, z, indexing="ij")
        Z = Z + 0.12 * X * Y
        grid = pv.StructuredGrid(X, Y, Z)
        return grid.cast_to_unstructured_grid()









.. GENERATED FROM PYTHON SOURCE LINES 36-38

Step 2: Convert to TensorMesh
-----------------------------

.. GENERATED FROM PYTHON SOURCE LINES 38-64

.. code-block:: Python

    def main() -> None:
        """Run the tutorial."""
        pv_mesh = make_volume_grid()
        mesh = graphlow.from_pyvista(pv_mesh, backend="torch")

        cell_types = [
            pv.CellType(int(cell_type)).name
            for cell_type in mesh.topology.unique_cell_types()
        ]

        print(f"Backend tensor type: {type(mesh.points).__name__}")
        print(f"Number of points: {mesh.n_points}")
        print(f"Number of cells: {mesh.n_cells}")
        print(f"Topological dimension: {mesh.topology.mesh_dim().name}")
        print(f"Cell types: {cell_types}")
        print(f"Point tensor shape: {tuple(mesh.points.shape)}")

        plotter = pv.Plotter(window_size=[800, 600])
        plotter.add_mesh(mesh.pvmesh, show_edges=True, color="lightgray")
        plotter.show_bounds(mesh=mesh.pvmesh, location="outer")
        plotter.camera_position = "iso"
        plotter.show()


    if __name__ == "__main__":
        main()



.. image-sg:: /example_gallery/auto_examples/basic/images/sphx_glr_create_tensor_mesh_001.png
   :alt: create tensor mesh
   :srcset: /example_gallery/auto_examples/basic/images/sphx_glr_create_tensor_mesh_001.png
   :class: sphx-glr-single-img


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

 .. code-block:: none

    Backend tensor type: Tensor
    Number of points: 36
    Number of cells: 12
    Topological dimension: VOLUME
    Cell types: ['HEXAHEDRON']
    Point tensor shape: (36, 3)





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

   **Total running time of the script:** (0 minutes 1.647 seconds)


.. _sphx_glr_download_example_gallery_auto_examples_basic_create_tensor_mesh.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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