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

.. only:: html

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

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

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

.. _sphx_glr_examples_frequencyseries_percentiles.py:


.. sectionauthor:: Duncan Macleod <duncan.macleod@ligo.org>
.. currentmodule:: gwpy.timeseries

Plotting an averaged ASD with percentiles.
##########################################

As we have seen in :ref:`sphinx_glr_examples_frequency_hoff`, the Amplitude
Spectral Density (ASD) is a key indicator of frequency-domain sensitivity for
a gravitational-wave detector.

However, the ASD doesn't allow you to see how much the sensitivity varies
over time.
One tool for that is the :ref:`spectrogram <gwpy-spectrogram>`, while another
is simply to show percentiles of a number of ASD measurements.

In this example we calculate the median ASD over 2048-seconds surrounding
the GW178017 event, and also the 5th and 95th percentiles of the ASD, and
plot them on a single figure.

.. GENERATED FROM PYTHON SOURCE LINES 41-44

Data access
-----------
First, as always, we get the data using :meth:`TimeSeries.fetch_open_data`:

.. GENERATED FROM PYTHON SOURCE LINES 44-48

.. code-block:: Python


    from gwpy.timeseries import TimeSeries
    hoft = TimeSeries.fetch_open_data("H1", 1187007040, 1187009088)








.. GENERATED FROM PYTHON SOURCE LINES 49-54

Calculate spectrogram
---------------------
Next we calculate a :class:`~gwpy.spectrogram.Spectrogram` by calculating
a number of ASDs, using the :meth:`~gwpy.timeseries.TimeSeries.spectrogram2`
method:

.. GENERATED FROM PYTHON SOURCE LINES 54-57

.. code-block:: Python


    sg = hoft.spectrogram2(fftlength=4, overlap=2, window="hann") ** (1 / 2.)








.. GENERATED FROM PYTHON SOURCE LINES 58-59

From this we can trivially extract the median, 5th and 95th percentiles:

.. GENERATED FROM PYTHON SOURCE LINES 59-64

.. code-block:: Python


    median = sg.percentile(50)
    low = sg.percentile(5)
    high = sg.percentile(95)








.. GENERATED FROM PYTHON SOURCE LINES 65-69

Visualisation
-------------
Finally, we can make plot, using :meth:`~gwpy.plot.Axes.plot_mmm` to
display the 5th and 95th percentiles as a shaded region around the median:

.. GENERATED FROM PYTHON SOURCE LINES 69-84

.. code-block:: Python


    from gwpy.plot import Plot
    plot = Plot()
    ax = plot.add_subplot(
        xscale="log",
        xlim=(10, 1500),
        xlabel="Frequency [Hz]",
        yscale="log",
        ylim=(3e-24, 2e-20),
        ylabel=r"Strain noise [1/$\sqrt{\mathrm{Hz}}$]",
    )
    ax.plot_mmm(median, low, high, color="gwpy:ligo-hanford")
    ax.set_title("LIGO-Hanford strain noise variation around GW170817")
    plot.show()




.. image-sg:: /examples/frequencyseries/images/sphx_glr_percentiles_001.png
   :alt: LIGO-Hanford strain noise variation around GW170817
   :srcset: /examples/frequencyseries/images/sphx_glr_percentiles_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 85-88

Now we can see that the ASD varies by factors of a few across most of the
frequency band, with notable exceptions, e.g. around the 60-Hz power line
harmonics (60 Hz, 120 Hz, 180 Hz, ...) where the noise is very stable.


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

   **Total running time of the script:** (0 minutes 1.843 seconds)


.. _sphx_glr_download_examples_frequencyseries_percentiles.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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