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

.. only:: html

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

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

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

.. _sphx_glr_examples_plot_filling_factor.py:


Filling factor of various sky grids for the Dorado mission
==========================================================

.. GENERATED FROM PYTHON SOURCE LINES 7-8

First, some imports.

.. GENERATED FROM PYTHON SOURCE LINES 8-18

.. code-block:: Python


    from functools import partial

    from astropy_healpix import HEALPix
    from astropy.coordinates import ICRS
    from astropy import units as u
    from dorado.scheduling import mission, skygrid
    from matplotlib import pyplot as plt
    import numpy as np








.. GENERATED FROM PYTHON SOURCE LINES 19-20

Select a HEALPix resolution for spatial calculations.

.. GENERATED FROM PYTHON SOURCE LINES 20-23

.. code-block:: Python


    hpx = HEALPix(nside=512, frame=ICRS())








.. GENERATED FROM PYTHON SOURCE LINES 24-25

Determine the area of the field of view.

.. GENERATED FROM PYTHON SOURCE LINES 25-29

.. code-block:: Python


    fov = mission.dorado().fov
    fov_area = len(fov.footprint_healpix(hpx)) * hpx.pixel_area








.. GENERATED FROM PYTHON SOURCE LINES 30-31

Compute the filling factor for all sky grid methods.

.. GENERATED FROM PYTHON SOURCE LINES 31-65

.. code-block:: Python


    methods = {
        'geodesic(class_="I")': partial(skygrid.geodesic, class_='I'),
        'geodesic(class_="II")': partial(skygrid.geodesic, class_='II'),
        'geodesic(class_="III")': partial(skygrid.geodesic, class_='III'),
        'golden_angle_spiral': skygrid.golden_angle_spiral,
        'sinusoidal': skygrid.sinusoidal
    }

    fig_width, fig_height = plt.rcParams['figure.figsize']
    fig, (ax1, ax2) = plt.subplots(
        1, 2, figsize=(2 * fig_width, fig_height), sharey=True)
    ax1.set_xlabel('Number of tiles')
    ax2.set_xlabel('Requested area per tile (deg$^2$)')
    ax1.set_ylabel('1 - filling factor')
    ax1.set_yscale('log')

    areas = np.geomspace(0.5 * fov_area, fov_area).to(u.deg**2)
    for method_name, method in methods.items():
        number_of_tiles = np.empty(len(areas), dtype=int)
        one_minus_fill_factors = np.empty(len(areas), dtype=float)
        for i, area in enumerate(areas):
            centers = method(area)
            rolls = np.asarray([0]) * u.deg
            pixels = set()
            for more_pixels, in fov.footprint_healpix_grid(hpx, centers, rolls):
                pixels |= set(more_pixels)
            number_of_tiles[i] = len(centers)
            one_minus_fill_factors[i] = 1 - len(pixels) / hpx.npix

        ax1.plot(number_of_tiles, one_minus_fill_factors, '.-', label=method_name)
        ax2.plot(areas, one_minus_fill_factors, '.-', label=method_name)

    ax1.legend()



.. image-sg:: /examples/images/sphx_glr_plot_filling_factor_001.png
   :alt: plot filling factor
   :srcset: /examples/images/sphx_glr_plot_filling_factor_001.png
   :class: sphx-glr-single-img


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

 .. code-block:: none


    <matplotlib.legend.Legend object at 0x7ff7bb50cfd0>




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

   **Total running time of the script:** (10 minutes 34.898 seconds)


.. _sphx_glr_download_examples_plot_filling_factor.py:

.. only:: html

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

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

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

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

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


.. only:: html

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

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