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

.. only:: html

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

        Click :ref:`here <sphx_glr_download_auto_examples_mesh_example_construct_mesh.py>`
        to download the full example code

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

.. _sphx_glr_auto_examples_mesh_example_construct_mesh.py:


================================================================================
Construct a Mesh from a .msh file
================================================================================

Mesh is constructed from a `.msh` and plotted.

.. GENERATED FROM PYTHON SOURCE LINES 9-15

.. code-block:: default


    import matplotlib.pyplot as plt
    import numpy as np
    import freshkiss3d as fk
    import freshkiss3d.extra.plots as fk_plt








.. GENERATED FROM PYTHON SOURCE LINES 16-22

Read a Mesh
--------------------

There is two ways to visualize a mesh from a file. You can either build a
TriangularMesh or directly use the read_msh function.


.. GENERATED FROM PYTHON SOURCE LINES 23-26

.. code-block:: default


    TG, vertex_labels, boundary_labels = fk.read_msh('inputs/tiny.msh')








.. GENERATED FROM PYTHON SOURCE LINES 27-32

.. warning::
   The read_msh function is compatible with ``.msh``, ``.msh`` (GMSH) and ``.mesh``
   (MEDIT) formats ONLY. Note that the ``.msh`` used in freshkiss3d isn't the 
   same as gmsh ``.msh`` format. 


.. GENERATED FROM PYTHON SOURCE LINES 35-38

Construct a TriangularMesh
------------------------------


.. GENERATED FROM PYTHON SOURCE LINES 39-46

.. code-block:: default


    triangular_mesh = fk.TriangularMesh.from_msh_file('inputs/tiny.msh')   

    TG = triangular_mesh.triangulation
    vertex_labels = triangular_mesh.vertex_labels
    boundary_edges = triangular_mesh.boundary_edges








.. GENERATED FROM PYTHON SOURCE LINES 47-51

.. note::
   When you build a TriangularMesh, the read_msh function is called in the 
   background


.. GENERATED FROM PYTHON SOURCE LINES 54-60

Basic plot
--------------------

To visualize the mesh with triplot you need to recover nodes coordonates (x,y) 
and triangles (trivtx)


.. GENERATED FROM PYTHON SOURCE LINES 61-69

.. code-block:: default


    x = np.asarray(TG.x)
    y = np.asarray(TG.y)
    trivtx = np.asarray(TG.trivtx)

    plt.triplot(x, y, trivtx)
    plt.show()




.. image-sg:: /auto_examples_mesh/images/sphx_glr_example_construct_mesh_001.png
   :alt: example construct mesh
   :srcset: /auto_examples_mesh/images/sphx_glr_example_construct_mesh_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 70-77

Fancy plot
--------------------

Basic plot isn't really helpfull when you need specific information about your 
mesh, for example node or boundary labels. So here is shown how to add life to 
your mesh plots:


.. GENERATED FROM PYTHON SOURCE LINES 78-107

.. code-block:: default


    colors = {0:'blue', 1:'red', 2:'green'}
    plt.figure(figsize=(8, 8))

     # Plot triangles.
    plt.triplot(x, y, trivtx)
    xtri = np.average(x[trivtx], axis=1)
    ytri = np.average(y[trivtx], axis=1)
    fk_plt.put_text_index(xtri, ytri, color='red')

    # Plot points.
    for a, b, label in zip(x, y, vertex_labels):
        plt.plot(a, b, marker='o', color=colors[label], markersize=10)
    fk_plt.put_text_index(x, y, offset=(0.04, 0.04))

    # Plot edges.
    for B in range(boundary_edges.size):
        i0 = boundary_edges.vertices[B, 0]
        i1 = boundary_edges.vertices[B, 1]
        x0, y0 = x[i0], y[i0]
        x1, y1 = x[i1], y[i1]
        plt.plot([x0, x1], [y0, y1], color=colors[boundary_edges.label[B]], linewidth=3.)

    plt.grid()
    plt.axis('scaled')
    plt.xlim(-0.5, 6.5)
    plt.ylim(9.5, 15.5)
    plt.show()




.. image-sg:: /auto_examples_mesh/images/sphx_glr_example_construct_mesh_002.png
   :alt: example construct mesh
   :srcset: /auto_examples_mesh/images/sphx_glr_example_construct_mesh_002.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** ( 0 minutes  0.295 seconds)


.. _sphx_glr_download_auto_examples_mesh_example_construct_mesh.py:

.. only:: html

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


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

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

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

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


.. only:: html

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

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