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

    Click :ref:`here <sphx_glr_download_modeling_gallery_spectral_plot_template_spectral.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_modeling_gallery_spectral_plot_template_spectral.py:


.. _template-spectral-model:

Template Spectral Model
=======================

This model is defined by custom tabular values.

The units returned will be the units of the values array provided at
initialization. The model will return values interpolated in
log-space, returning 0 for energies outside of the limits of the provided
energy array.

The class implementation follows closely what has been done in
`naima.models.TemplateSpectralModel`

Example plot
------------
Here is an example plot of the model:


.. code-block:: default


    import numpy as np
    from astropy import units as u
    import matplotlib.pyplot as plt
    from gammapy.modeling.models import Models, SkyModel, TemplateSpectralModel

    energy_range = [0.1, 1] * u.TeV
    energy = np.array([1e6, 3e6, 1e7, 3e7]) * u.MeV
    values = np.array([4.4e-38, 2.0e-38, 8.8e-39, 3.9e-39]) * u.Unit("MeV-1 s-1 cm-2")
    model = TemplateSpectralModel(energy=energy, values=values)
    model.plot(energy_range)
    plt.grid(which="both")




.. image:: /modeling/gallery/spectral/images/sphx_glr_plot_template_spectral_001.png
    :class: sphx-glr-single-img





YAML representation
-------------------
Here is an example YAML file using the model:


.. code-block:: default


    model = SkyModel(spectral_model=model, name="template-model")
    models = Models([model])

    print(models.to_yaml())




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

 Out:

 .. code-block:: none

    components:
    -   name: template-model
        type: SkyModel
        spectral:
            type: TemplateSpectralModel
            parameters:
            - {name: norm, value: 1.0, unit: '', min: .nan, max: .nan, frozen: false}
            - {name: tilt, value: 0.0, unit: '', min: .nan, max: .nan, frozen: true}
            - {name: reference, value: 1.0, unit: TeV, min: .nan, max: .nan, frozen: true}
            energy:
                data: [1000000.0, 3000000.0, 10000000.0, 30000000.0]
                unit: MeV
            values:
                data: [4.4e-38, 2.0e-38, 8.8e-39, 3.9e-39]
                unit: 1 / (cm2 MeV s)






.. _sphx_glr_download_modeling_gallery_spectral_plot_template_spectral.py:


.. only :: html

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



  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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


.. only:: html

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

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