.. only:: html .. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_modeling_gallery_spectral_plot_exp_cutoff_powerlaw.py: .. _exp-cutoff-powerlaw-spectral-model: Exponential Cutoff Powerlaw Spectral Model ========================================== This model parametrises a cutoff power law spectrum. It is defined by the following equation: .. math:: \phi(E) = \phi_0 \cdot \left(\frac{E}{E_0}\right)^{-\Gamma} \exp(- {(\lambda E})^{\alpha}) Example plot ------------ Here is an example plot of the model: .. code-block:: default from astropy import units as u import matplotlib.pyplot as plt from gammapy.modeling.models import ExpCutoffPowerLawSpectralModel, Models, SkyModel energy_range = [0.1, 100] * u.TeV model = ExpCutoffPowerLawSpectralModel( amplitude=1e-12 * u.Unit("cm-2 s-1 TeV-1"), index=2, lambda_=0.1 * u.Unit("TeV-1"), reference=1 * u.TeV, ) model.plot(energy_range) plt.grid(which="both") .. image:: /modeling/gallery/spectral/images/sphx_glr_plot_exp_cutoff_powerlaw_001.png :alt: plot exp cutoff powerlaw :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="exp-cutoff-power-law-model") models = Models([model]) print(models.to_yaml()) .. rst-class:: sphx-glr-script-out Out: .. code-block:: none components: - name: exp-cutoff-power-law-model type: SkyModel spectral: type: ExpCutoffPowerLawSpectralModel parameters: - name: index value: 2.0 - name: amplitude value: 1.0e-12 unit: cm-2 s-1 TeV-1 - name: reference value: 1.0 unit: TeV frozen: true - name: lambda_ value: 0.1 unit: TeV-1 - name: alpha value: 1.0 frozen: true .. _sphx_glr_download_modeling_gallery_spectral_plot_exp_cutoff_powerlaw.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_exp_cutoff_powerlaw.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_exp_cutoff_powerlaw.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_