.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples_mesh/example_generate_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_generate_mesh.py>`
        to download the full example code

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

.. _sphx_glr_auto_examples_mesh_example_generate_mesh.py:


================================================================================
Generate meshes from .geo files with Gmsh
================================================================================

Meshes are built with gmsh from `.geo` files then loaded into freshkiss3d.

.. GENERATED FROM PYTHON SOURCE LINES 9-14

.. code-block:: default

    import os
    import numpy as np
    import matplotlib.pyplot as plt
    import freshkiss3d as fk








.. GENERATED FROM PYTHON SOURCE LINES 15-48

Generate meshes from .geo
--------------------------

Meshes are generated with gmsh thanks to a ``.geo`` file. The ``.geo`` contains 
all information gmsh needs to generate a Delaunay triangulation. You can specify
the number of nodes on boundaries with the `Transfinite` option.

.. note::

    .geo files can be generated with gsmh and are easy to script for simple geometries.
    Here is an example of a simple canal geometry:    

    .. code-block:: bash

        Lx = 25.0;
        Ly = 1.0;
        Point(1) = {0, 0, 0, 1};
        Point(2) = {Lx, 0, 0, 1};
        Point(3) = {Lx, Ly, 0, 1};
        Point(4) = {0, Ly, 0, 1};
        Line(1) = {1, 2};
        Line(2) = {2, 3};
        Line(3) = {3, 4};
        Line(4) = {4, 1};
        Line Loop(5) = {3, 4, 1, 2};
        Plane Surface(0) = {5};
        Physical Line(1) = {4};
        Physical Line(2) = {2};
        Physical Line(3) = {3};
        Physical Line(4) = {1};
        Transfinite Line {3, 1} = 50 Using Progression 1;
        Transfinite Line {4, 2} = 3 Using Progression 1;
        Physical Surface(0) = {0};

.. GENERATED FROM PYTHON SOURCE LINES 51-52

Gmsh can be called via simple commands to generate meshes:

.. GENERATED FROM PYTHON SOURCE LINES 53-57

.. code-block:: default


    os.system('gmsh -2 -format msh2 inputs/bump0.geo -o inputs/bump0.msh')
    os.system('gmsh -2 -format msh2 inputs/bump1.geo -o inputs/bump1.msh')





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

 .. code-block:: none


    0



.. GENERATED FROM PYTHON SOURCE LINES 58-61

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


.. GENERATED FROM PYTHON SOURCE LINES 62-67

.. code-block:: default


    triangular_mesh_1 = fk.TriangularMesh.from_msh_file('inputs/bump0.msh')
    triangular_mesh_2 = fk.TriangularMesh.from_msh_file('inputs/bump1.msh')









.. GENERATED FROM PYTHON SOURCE LINES 68-71

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


.. GENERATED FROM PYTHON SOURCE LINES 72-100

.. code-block:: default


    TG = triangular_mesh_1.triangulation
    x = np.asarray(TG.x)
    y = np.asarray(TG.y)
    trivtx = np.asarray(TG.trivtx)

    TG_r = triangular_mesh_2.triangulation
    x_r = np.asarray(TG_r.x)
    y_r = np.asarray(TG_r.y)
    trivtx_r = np.asarray(TG_r.trivtx)

    plt.rcParams["figure.figsize"]=[20,6]
    fig = plt.figure()

    # Plot 
    ax1 = fig.add_subplot(211)
    ax1.triplot(x, y, trivtx, color='r')
    ax1.set_title("Mesh 1")

    # Plot refined mesh
    ax2 = fig.add_subplot(212)
    ax2.triplot(x_r, y_r, trivtx_r)
    ax2.set_title("Mesh 2")

    plt.show()

    #os.system('rm inputs/bump0.msh')
    #os.system('rm inputs/bump1.msh')



.. image-sg:: /auto_examples_mesh/images/sphx_glr_example_generate_mesh_001.png
   :alt: Mesh 1, Mesh 2
   :srcset: /auto_examples_mesh/images/sphx_glr_example_generate_mesh_001.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** ( 0 minutes  0.444 seconds)


.. _sphx_glr_download_auto_examples_mesh_example_generate_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_generate_mesh.py <example_generate_mesh.py>`

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

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


.. only:: html

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

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