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

.. only:: html

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

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

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

.. _sphx_glr_gallery_plot_speed_of_sound.py:


Speed of Sound
==============

This example shows how to compute the speed of sound by fitting phonon frequencies
along selected directions by linear least-squares fit.
For a command line interface use:

.. code-block:: bash

    abiview.py ddb_vs DDB_FILE

.. GENERATED FROM PYTHON SOURCE LINES 16-17

Initialize object from DDB file.

.. GENERATED FROM PYTHON SOURCE LINES 17-27

.. code-block:: Python


    import os
    import abipy.data as abidata

    from abipy import abilab
    from abipy.dfpt.vsound import SoundVelocity

    ddb_path = os.path.join(abidata.dirpath, "refs", "si_sound_vel", "Si_DDB")
    sv = SoundVelocity.from_ddb(ddb_path)








.. GENERATED FROM PYTHON SOURCE LINES 28-29

Get pandas dataframe with results.

.. GENERATED FROM PYTHON SOURCE LINES 29-33

.. code-block:: Python


    df = sv.get_dataframe()
    abilab.print_dataframe(df)








.. GENERATED FROM PYTHON SOURCE LINES 34-35

Plot fit with matplotlib

.. GENERATED FROM PYTHON SOURCE LINES 35-38

.. code-block:: Python


    sv.plot()




.. image-sg:: /gallery/images/sphx_glr_plot_speed_of_sound_001.png
   :alt: [0.707, 0.000, 0.707] - X, [0.408, 0.408, 0.816] - K, [0.577, 0.577, 0.577] - L
   :srcset: /gallery/images/sphx_glr_plot_speed_of_sound_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 39-40

Plot fit with plotly

.. GENERATED FROM PYTHON SOURCE LINES 40-42

.. code-block:: Python


    sv.plotly(template="plotly_dark")








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

   **Total running time of the script:** (0 minutes 1.669 seconds)


.. _sphx_glr_download_gallery_plot_speed_of_sound.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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