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

.. only:: html

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

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

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

.. _sphx_glr_gallery_other_plot_constellation.py:


Constellation
=============

This example shows how to use ``iplotx`` to plot constellations. Data comes from Wikipedia: https://en.wikipedia.org/wiki/List_of_stars_in_Draco.

.. GENERATED FROM PYTHON SOURCE LINES 8-96

.. code-block:: Python


    import matplotlib.pyplot as plt
    import networkx as nx
    import pandas as pd
    import iplotx as ipx


    def convert_ra(ra):
        """Convert right ascension from hours, minutes, seconds to degrees."""
        hours, minutes, seconds = ra.split()
        lon_deg = 15.0 * (int(hours.rstrip("h")) + int(minutes.rstrip("m")) / 60 + float(seconds.rstrip("s")) / 3600)
        return -lon_deg


    def convert_dec(dec):
        """Convert declination from degrees, minutes, seconds to degrees."""
        deg, min, sec = dec.split()
        lat_deg = int(deg[:-1]) + int(min[:-1]) / 60 + float(sec[:-1]) / 3600
        return lat_deg


    # Load star information
    star_info = pd.read_csv(
        "data/draco_stars.csv",
        sep="\t",
    )

    # Limit to visible stars with a Bayer designation
    star_info = star_info.dropna(subset="B").set_index("Name", drop=False)

    # Compute angular coordinates in degrees
    star_info["lon"] = star_info["RA"].apply(convert_ra)
    star_info["lat"] = star_info["Dec"].apply(convert_dec)

    g = nx.from_edgelist([
        ("γ Dra", "β Dra"),
        ("β Dra", "ν2 Dra"),
        ("ν2 Dra", "ξ Dra"),
        ("ξ Dra", "γ Dra"),
        ("ξ Dra", "δ Dra"),
        ("δ Dra", "ε Dra"),
        ("δ Dra", "φ Dra"),
        ("φ Dra", "χ Dra"),
        ("φ Dra", "ω Dra"),
        ("ω Dra", "ζ Dra"),
        ("ζ Dra", "η Dra"),
        ("η Dra", "θ Dra"),
        ("θ Dra", "ι Dra"),
        ("ι Dra", "Thuban"),
        ("Thuban", "κ Dra"),
        ("κ Dra", "λ Dra"),
    ])


    star_info = star_info.loc[list(g.nodes)]

    # Strip the " Dra" suffix for labeling, since the constellation is known
    labels = {n: n.rstrip(" Dra") for n in g.nodes}

    # Create a size that correlates with magnitude (brighter stars are larger)
    scale = star_info["vis. mag."].min() - star_info["vis. mag."].max()
    star_size = 13 - 15 * (star_info["vis. mag."].max() - star_info["vis. mag."]) / scale

    # Plot the constellation
    fig, ax = plt.subplots(figsize=(9, 6))
    ax.patch.set_facecolor("black")
    artist = ipx.network(
        g,
        layout=star_info[["lon", "lat"]],
        ax=ax,
        vertex_facecolor=star_info["vis. mag."],
        vertex_cmap="viridis_r",
        vertex_edgecolor="white",
        edge_color="white",
        edge_linewidth=2,
        vertex_alpha=0.8,
        vertex_label_color="white",
        vertex_size=star_size,
        vertex_label_size=14,
        title="Stars of the Draco constellation",
        edge_curved=False,
        node_labels=labels,
    )[0]

    # Add colorbar based on star magnitude
    fig.colorbar(artist.get_nodes(), ax=ax, label="Visual Magnitude", orientation="vertical", pad=0.02)





.. image-sg:: /gallery/other/images/sphx_glr_plot_constellation_001.png
   :alt: Stars of the Draco constellation
   :srcset: /gallery/other/images/sphx_glr_plot_constellation_001.png
   :class: sphx-glr-single-img


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

 .. code-block:: none


    <matplotlib.colorbar.Colorbar object at 0x7dd1a600f4d0>



.. GENERATED FROM PYTHON SOURCE LINES 97-100

.. note::
  Angular coordinates are taken to have a Cartesian meaning for the sake of simplicity. This leads to some distorsion compared
  to how the real constellation looks like on a celestial sphere.


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

   **Total running time of the script:** (0 minutes 0.101 seconds)


.. _sphx_glr_download_gallery_other_plot_constellation.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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