.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/2D_1_examples/plot_0_astronomy.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_auto_examples_2D_1_examples_plot_0_astronomy.py>`
        to download the full example code

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

.. _sphx_glr_auto_examples_2D_1_examples_plot_0_astronomy.py:


Astronomy dataset
^^^^^^^^^^^^^^^^^

.. GENERATED FROM PYTHON SOURCE LINES 6-14

The following dataset is a new observation of the Bubble Nebula
acquired by `The Hubble Heritage Team
<https://archive.stsci.edu/prepds/heritage/bubble/introduction.html>`_,
in February 2016. The original dataset was obtained in the FITS format
and subsequently converted to the CSD model file-format. For the convenience of
illustration, we have downsampled the original dataset.

Let's load the `.csdfe` file and look at its data structure.

.. GENERATED FROM PYTHON SOURCE LINES 14-23

.. code-block:: Python

    import matplotlib.pyplot as plt

    import csdmpy as cp

    domain = "https://www.ssnmr.org/sites/default/files/CSDM"
    filename = f"{domain}/BubbleNebula/Bubble_nebula.csdf"
    bubble_nebula = cp.load(filename)
    print(bubble_nebula.data_structure)





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

 .. code-block:: none

    {
      "csdm": {
        "version": "1.0",
        "timestamp": "2020-01-04T01:43:31Z",
        "description": "The dataset is a new observation of the Bubble Nebula acquired by The Hubble Heritage Team, in February 2016.",
        "dimensions": [
          {
            "type": "linear",
            "count": 1024,
            "increment": "-0.0002581136196 °",
            "coordinates_offset": "350.311874957 °",
            "quantity_name": "plane angle",
            "label": "Right Ascension"
          },
          {
            "type": "linear",
            "count": 1024,
            "increment": "0.0001219957797701109 °",
            "coordinates_offset": "61.12851494969163 °",
            "quantity_name": "plane angle",
            "label": "Declination"
          }
        ],
        "dependent_variables": [
          {
            "type": "internal",
            "name": "Bubble Nebula, 656nm",
            "numeric_type": "float32",
            "quantity_type": "scalar",
            "components": [
              [
                "0.0, 0.0, ..., 0.0, 0.0"
              ]
            ]
          }
        ]
      }
    }




.. GENERATED FROM PYTHON SOURCE LINES 24-28

Here, the variable ``bubble_nebula`` is an instance of the :ref:`csdm_api`
class. From the data structure, one finds two dimensions, labeled as
*Right Ascension* and *Declination*, and one single-component dependent
variable named *Bubble Nebula, 656nm*.

.. GENERATED FROM PYTHON SOURCE LINES 30-32

Let's get the tuple of the dimension and dependent variable instances from
the ``bubble_nebula`` instance following,

.. GENERATED FROM PYTHON SOURCE LINES 32-35

.. code-block:: Python

    x = bubble_nebula.dimensions
    y = bubble_nebula.dependent_variables








.. GENERATED FROM PYTHON SOURCE LINES 36-40

There are two dimension instances in ``x``. Let's look
at the coordinates along each dimension, using the
:attr:`~csdmpy.Dimension.coordinates` attribute of the
respective instances.

.. GENERATED FROM PYTHON SOURCE LINES 42-44

.. code-block:: Python

    print(x[0].coordinates[:10])





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

 .. code-block:: none

    [350.31187496 350.31161684 350.31135873 350.31110062 350.3108425
     350.31058439 350.31032628 350.31006816 350.30981005 350.30955193] deg




.. GENERATED FROM PYTHON SOURCE LINES 45-47

.. code-block:: Python

    print(x[1].coordinates[:10])





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

 .. code-block:: none

    [61.12851495 61.12863695 61.12875894 61.12888094 61.12900293 61.12912493
     61.12924692 61.12936892 61.12949092 61.12961291] deg




.. GENERATED FROM PYTHON SOURCE LINES 48-49

Here, we only print the first ten coordinates along the respective dimensions.

.. GENERATED FROM PYTHON SOURCE LINES 51-53

The component of the dependent variable is accessed through the
:attr:`~csdmpy.DependentVariable.components` attribute.

.. GENERATED FROM PYTHON SOURCE LINES 53-55

.. code-block:: Python

    y00 = y[0].components[0]








.. GENERATED FROM PYTHON SOURCE LINES 56-57

**Visualize the dataset**

.. GENERATED FROM PYTHON SOURCE LINES 57-64

.. code-block:: Python

    from matplotlib.colors import LogNorm

    plt.figure(figsize=(6, 4.5))
    ax = plt.subplot(projection="csdm")
    ax.imshow(bubble_nebula, norm=LogNorm(vmin=7.5e-3, clip=True), aspect="auto")
    plt.tight_layout()
    plt.show()



.. image-sg:: /auto_examples/2D_1_examples/images/sphx_glr_plot_0_astronomy_001.png
   :alt: Bubble Nebula, 656nm
   :srcset: /auto_examples/2D_1_examples/images/sphx_glr_plot_0_astronomy_001.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 0.595 seconds)


.. _sphx_glr_download_auto_examples_2D_1_examples_plot_0_astronomy.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: plot_0_astronomy.ipynb <plot_0_astronomy.ipynb>`

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

      :download:`Download Python source code: plot_0_astronomy.py <plot_0_astronomy.py>`


.. only:: html

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

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