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

.. only:: html

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

        Run this example online :

        - Click :ref:`here <sphx_glr_download_auto_examples_calc_hitran_full_range.py>`
          to download the full example code

        - Then start `Radis-Lab <https://radis.github.io/radis-lab/>`__,
          upload the Jupyter notebook, and run it from there.

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

.. _sphx_glr_auto_examples_calc_hitran_full_range.py:


.. _example_hitran_full_range:

===============================
Calculate a full range spectrum
===============================

We compute the transmittance of an homogeneous, 1-km atmosphere layer
at 300 K and 1 atm, with 420 ppm CO2 and 2% H2O.

This example makes use of a lot of the RADIS optimization and convenience functions :

- The database is retrieved from the latest HITRAN data using [HAPI]_, parsed
  with RADIS and stored to memory-mapping formats. After the first calls,
  retrieving the database will be very fast

- The RADIS algorithm includes a sparse wavenumber implementation, which is
  activated by default in the following example where the waverange is very
  large. This behavior can be changed by setting the `SPARSE_WAVENUMBER` key
  of the :py:attr:`radis.config` dictionary, or of the ~/radis.json user file.

- The wavenumber grid is automatically computed using the `wstep='auto'` parameter.

- A linestrength cutoff reduces the initial number of lines.

Eventually, the full-range spectrum (about 4.8M points) is computed within a minute,
with about 140k lines resolved, i.e. a performance of about 1e10 gridpoints*lines/s.

Extra optimization could be achieved by cutting the spectrum in small intervals,
but requires an a-priori knowledge of the absorption & emission ranges of the
spectrum. See the :ref:`Calculate a large spectrum by part <example_large_range_by_part>`

.. GENERATED FROM PYTHON SOURCE LINES 39-58

.. code-block:: default


    import astropy.units as u

    from radis import calc_spectrum

    s = calc_spectrum(
        wmin=0.5 * u.um,
        wmax=15 * u.um,  # cm-1
        mole_fraction={"CO2": 420e-6, "H2O": 0.02},
        isotope="1,2,3",
        pressure=1.01325,  # bar
        Tgas=300,  # K
        path_length=1e5,  # 1 km in cm
        verbose=2,
        databank="hitran",
        wstep="auto",
    )



.. GENERATED FROM PYTHON SOURCE LINES 59-61

Plot low and high resolution spectra on the same graph :


.. GENERATED FROM PYTHON SOURCE LINES 61-69

.. code-block:: default

    s.apply_slit(10, "nm")
    import matplotlib.pyplot as plt

    plt.figure(figsize=(16, 6))
    s.plot("transmittance_noslit", wunit="nm", color="k", alpha=0.1, nfig="same")
    s.plot("transmittance", wunit="nm", color="k", nfig="same")



.. GENERATED FROM PYTHON SOURCE LINES 70-72

Print some details about the computed spectrum :
We could also simply use `print(s)`

.. GENERATED FROM PYTHON SOURCE LINES 72-84

.. code-block:: default


    print("Number of grid points: ", len(s))
    print(
        "Number of lines: ", s.c["total_lines"]
    )  # some are discarded by linestrength cutoff
    print("Number of lines: ", s.c["lines_calculated"])
    print("Whether the sparse wavenumber algorithm was activated: ", s.c["sparse_ldm"])
    print(f"Lineshape truncation used: {s.c['truncation']:.1f}cm-1")
    print(f"Total calculation time: {s.c['calculation_time']:.1f}s")
    print(
        f"Gridpoints * lines/s : {len(s)*s.c['lines_calculated']/s.c['calculation_time']:.1e}"
    )


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

   **Total running time of the script:** ( 0 minutes  0.000 seconds)


.. _sphx_glr_download_auto_examples_calc_hitran_full_range.py:

.. only:: html

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


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

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

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

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