PiecewiseNormSpectralModel#
- class gammapy.modeling.models.PiecewiseNormSpectralModel(energy, norms=None, interp='log')[source]#
Bases:
gammapy.modeling.models.spectral.SpectralModel
- Piecewise spectral correction
with a free normalization at each fixed energy nodes.
For more information see Piecewise norm spectral model.
- Parameters
- energy
Quantity
Array of energies at which the model values are given (nodes).
- norms
ndarray
or list ofParameter
Array with the initial norms of the model at energies
energy
. A normalisation parameters is created for each value. Default is one at each node.- interpstr
Interpolation scaling in {“log”, “lin”}. Default is “log”
- energy
Attributes Summary
Energy nodes
Frozen status of a model, True if all parameters are frozen
Whether model is a norm spectral model
Norm values
Parameters (
Parameters
)Methods Summary
__call__
(energy)Call self as a function.
copy
(**kwargs)energy_flux
(energy_min, energy_max, **kwargs)Compute energy flux in given energy range.
energy_flux_error
(energy_min, energy_max[, ...])Evaluate the error of the energy flux of a given spectrum in
evaluate
(energy, **norms)evaluate_error
(energy[, epsilon])Evaluate spectral model with error propagation.
freeze
()Freeze all parameters
from_dict
(data)Create model from dict
from_parameters
(parameters, **kwargs)Create model from parameters
integral
(energy_min, energy_max, **kwargs)Integrate spectral model numerically if no analytical solution defined.
integral_error
(energy_min, energy_max[, epsilon])Evaluate the error of the integral flux of a given spectrum in a given energy range.
inverse
(value[, energy_min, energy_max])Return energy for a given function value of the spectral model.
inverse_all
(values[, energy_min, energy_max])Return energies for multiple function values of the spectral model.
plot
(energy_bounds[, ax, sed_type, ...])Plot spectral model curve.
plot_error
(energy_bounds[, ax, sed_type, ...])Plot spectral model error band.
reassign
(datasets_names, new_datasets_names)Reassign a model from one dataset to another
reference_fluxes
(energy_axis)Get reference fluxes for a given energy axis.
spectral_index
(energy[, epsilon])Compute spectral index at given energy.
to_dict
([full_output])Create dict for YAML serialisation
unfreeze
()Restore parameters frozen status to default
Attributes Documentation
- covariance#
- default_parameters = <gammapy.modeling.parameter.Parameters object>#
- energy#
Energy nodes
- frozen#
Frozen status of a model, True if all parameters are frozen
- is_norm_spectral_model#
Whether model is a norm spectral model
- norms#
Norm values
- parameters#
Parameters (
Parameters
)
- tag = ['PiecewiseNormSpectralModel', 'piecewise-norm']#
- type#
Methods Documentation
- __call__(energy)#
Call self as a function.
- copy(**kwargs)#
- energy_flux(energy_min, energy_max, **kwargs)#
Compute energy flux in given energy range.
\[G(E_{min}, E_{max}) = \int_{E_{min}}^{E_{max}} E \phi(E) dE\]- Parameters
- energy_min, energy_max
Quantity
Lower and upper bound of integration range.
- **kwargsdict
Keyword arguments passed to func:
integrate_spectrum
- energy_min, energy_max
- energy_flux_error(energy_min, energy_max, epsilon=0.0001, **kwargs)#
- Evaluate the error of the energy flux of a given spectrum in
a given energy range.
- Parameters
- energy_min, energy_max
Quantity
Lower and upper bound of integration range.
- epsilonfloat
Step size of the gradient evaluation. Given as a fraction of the parameter error.
- energy_min, energy_max
- Returns
- energy_flux, energy_flux_errtuple of
Quantity
Energy flux and energy flux error between energy_min and energy_max.
- energy_flux, energy_flux_errtuple of
- evaluate_error(energy, epsilon=0.0001)#
Evaluate spectral model with error propagation.
- freeze()#
Freeze all parameters
- integral(energy_min, energy_max, **kwargs)#
Integrate spectral model numerically if no analytical solution defined.
\[F(E_{min}, E_{max}) = \int_{E_{min}}^{E_{max}} \phi(E) dE\]- Parameters
- energy_min, energy_max
Quantity
Lower and upper bound of integration range.
- **kwargsdict
Keyword arguments passed to
integrate_spectrum()
- energy_min, energy_max
- integral_error(energy_min, energy_max, epsilon=0.0001, **kwargs)#
Evaluate the error of the integral flux of a given spectrum in a given energy range.
- inverse(value, energy_min=<Quantity 0.1 TeV>, energy_max=<Quantity 100. TeV>)#
Return energy for a given function value of the spectral model.
Calls the
scipy.optimize.brentq
numerical root finding method.
- inverse_all(values, energy_min=<Quantity 0.1 TeV>, energy_max=<Quantity 100. TeV>)#
Return energies for multiple function values of the spectral model.
Calls the
scipy.optimize.brentq
numerical root finding method.
- plot(energy_bounds, ax=None, sed_type='dnde', energy_power=0, n_points=100, **kwargs)#
Plot spectral model curve.
kwargs are forwarded to
matplotlib.pyplot.plot
By default a log-log scaling of the axes is used, if you want to change the y axis scaling to linear you can use:
from gammapy.modeling.models import ExpCutoffPowerLawSpectralModel from astropy import units as u pwl = ExpCutoffPowerLawSpectralModel() ax = pwl.plot(energy_bounds=(0.1, 100) * u.TeV) ax.set_yscale('linear')
- Parameters
- ax
Axes
, optional Axis
- energy_bounds
Quantity
Plot energy bounds passed to MapAxis.from_energy_bounds
- sed_type{“dnde”, “flux”, “eflux”, “e2dnde”}
Evaluation methods of the model
- energy_powerint, optional
Power of energy to multiply flux axis with
- n_pointsint, optional
Number of evaluation nodes
- **kwargsdict
Keyword arguments forwarded to
plot
- ax
- Returns
- ax
Axes
, optional Axis
- ax
- plot_error(energy_bounds, ax=None, sed_type='dnde', energy_power=0, n_points=100, **kwargs)#
Plot spectral model error band.
Note
This method calls
ax.set_yscale("log", nonpositive='clip')
andax.set_xscale("log", nonposx='clip')
to create a log-log representation. The additional argumentnonposx='clip'
avoids artefacts in the plot, when the error band extends to negative values (see also https://github.com/matplotlib/matplotlib/issues/8623).When you call
plt.loglog()
orplt.semilogy()
explicitly in your plotting code and the error band extends to negative values, it is not shown correctly. To circumvent this issue also useplt.loglog(nonposx='clip', nonpositive='clip')
orplt.semilogy(nonpositive='clip')
.- Parameters
- ax
Axes
, optional Axis
- energy_bounds
Quantity
Plot energy bounds passed to MapAxis.from_energy_bounds
- sed_type{“dnde”, “flux”, “eflux”, “e2dnde”}
Evaluation methods of the model
- energy_powerint, optional
Power of energy to multiply flux axis with
- n_pointsint, optional
Number of evaluation nodes
- **kwargsdict
Keyword arguments forwarded to
matplotlib.pyplot.fill_between
- ax
- Returns
- ax
Axes
, optional Axis
- ax
- reassign(datasets_names, new_datasets_names)#
Reassign a model from one dataset to another
- Parameters
- datasets_namesstr or list
Name of the datasets where the model is currently defined
- new_datasets_namesstr or list
Name of the datasets where the model should be defined instead. If multiple names are given the two list must have the save length, as the reassignment is element-wise.
- Returns
- model
Model
Reassigned model.
- model
- reference_fluxes(energy_axis)#
Get reference fluxes for a given energy axis.
- Parameters
- energy_axis
MapAxis
Energy axis
- energy_axis
- Returns
- fluxesdict of
Quantity
Reference fluxes
- fluxesdict of
- spectral_index(energy, epsilon=1e-05)#
Compute spectral index at given energy.
- Parameters
- energy
Quantity
Energy at which to estimate the index
- epsilonfloat
Fractional energy increment to use for determining the spectral index.
- energy
- Returns
- indexfloat
Estimated spectral index.
- unfreeze()#
Restore parameters frozen status to default