docs: added a simple example for XdfmWriter

.. toctree::

   :glob:

   Examples/*

 No newline at end of file

   Examples/WriteXdmf

   Examples/TwoInclusions

   Examples/PrePostDeepLearning

 No newline at end of file

from BasicTools.Containers import UnstructuredMesh

from BasicTools.IO.XdmfWriter import WriteMeshToXdmf

from BasicTools.Containers import UnstructuredMeshCreationTools as UMCT

from scipy.spatial import Delaunay

import numpy as np

def create_mesh_example() -> UnstructuredMesh:

    """This function creates a dummy mesh using Delaunay triangulation.

    """

    # Create a grid of points

    x, y = np.meshgrid(np.linspace(0,1,10), np.linspace(0,1,10))

    points = np.stack([x.ravel(), y.ravel()], axis=1)

    # Generate the triangles with Delaunay

    tri = Delaunay(points)

    triangles = tri.simplices

    # Create a BasicTools UnstructuredMesh using the CreateMeshOfTriangles utility

    mesh = UMCT.CreateMeshOfTriangles(points, triangles)

    return mesh

if __name__ == "__main__":

    # Create a simple mesh

    mesh = create_mesh_example()

    # Make six dummy nodal fields

    fields = np.random.randn(mesh.GetNumberOfNodes(), 6)

    # Dump the mesh and nodal fields into a XDMF file

    WriteMeshToXdmf(filename="WriteXdmf.xdmf",                          # path where the file will be stored

                    baseMeshObject=mesh,                                # UnstructuredMesh object 

                    PointFields=[fields[:,i] for i in range(6)],        # list of scalar fields

                    PointFieldsNames=[f"field_{i}" for i in range(6)],  # list of names for each scalar field

    )

 No newline at end of file

**************************

Dump mesh into a XDMF file

**************************

This small example shows how to dump a mesh and fields into a XDMF file that can be read by ParaView.

.. literalinclude:: WriteXdmf.py

   :language: python

   :emphasize-lines: 22-33

   :linenos:

 No newline at end of file