LightCurveEstimator

class gammapy.estimators.LightCurveEstimator(time_intervals=None, atol='1e-6 s', **kwargs)

Bases: gammapy.estimators.FluxPointsEstimator

Estimate light curve.

The estimator will fit the norm of the source model component to datasets in each of the provided time intervals.

If no time intervals are provided, the estimator will use the time intervals defined by the datasets GTIs.

To be included in the estimation, the dataset must have their GTI fully overlapping a time interval.

Time intervals without any dataset GTI fully overlapping will be dropped. They will not be stored in the final lightcurve FluxPoints object.

Parameters

time_intervalslist of astropy.time.Time

Start and stop time for each interval to compute the LC

sourcestr or int

For which source in the model to compute the flux points. Default is 0

energy_edgesQuantity

Energy edges of the light curve.

atolQuantity

Tolerance value for time comparison with different scale. Default 1e-6 sec.

norm_minfloat

Minimum value for the norm used for the fit statistic profile evaluation.

norm_maxfloat

Maximum value for the norm used for the fit statistic profile evaluation.

norm_n_valuesint

Number of norm values used for the fit statistic profile.

norm_valuesnumpy.ndarray

Array of norm values to be used for the fit statistic profile.

n_sigmaint

Number of sigma to use for asymmetric error computation. Default is 1.

n_sigma_ulint

Number of sigma to use for upper limit computation. Default is 2.

selection_optionallist of str

Which steps to execute. Available options are:

• “all”: all the optional steps are executed

• “errn-errp”: estimate asymmetric errors.

• “ul”: estimate upper limits.

• “scan”: estimate fit statistic profiles.

Default is None so the optional steps are not executed.

fitFit

Fit instance specifying the backend and fit options.

reoptimizebool

Re-optimize other free model parameters. Default is True.

Attributes Summary

config_parameters	Config parameters
selection_optional
tag

Methods Summary

copy()	Copy estimator
estimate_best_fit(datasets, parameter)	Estimate parameter asymmetric errors
estimate_counts(datasets)	Estimate counts for the flux point.
estimate_errn_errp(datasets, parameter)	Estimate parameter asymmetric errors
estimate_flux_point(datasets, energy_min, …)	Estimate flux point for a single energy group.
estimate_npred(datasets)	Estimate npred for the flux point.
estimate_npred_excess(datasets)	Estimate npred excess for the source.
estimate_scan(datasets, parameter)	Estimate parameter stat scan.
estimate_time_bin_flux(datasets)	Estimate flux point for a single energy group.
estimate_ts(datasets, parameter)	Estimate parameter ts
estimate_ul(datasets, parameter)	Estimate parameter ul.
expand_map(m, dataset_names)	Expand map in dataset axis
get_scale_model(models)	Set scale model
run(datasets)	Run light curve extraction.

Attributes Documentation

config_parameters

Config parameters

selection_optional

tag = 'LightCurveEstimator'

Methods Documentation

copy()

Copy estimator

estimate_best_fit(datasets, parameter)

Estimate parameter asymmetric errors

Parameters

datasetsDatasets

Datasets

parameterParameter

For which parameter to get the value

Returns

resultdict

Dict with the various parameter estimation values. Entries are:

• parameter.name: best fit parameter value

• “stat”: best fit total stat.

• “success”: boolean flag for fit success

• parameter.name_err: covariance-based error estimate on parameter value

static estimate_counts(datasets)

Estimate counts for the flux point.

Parameters

datasetsDatasets

Datasets

Returns

resultdict

Dict with an array with one entry per dataset with the sum of the masked counts.

estimate_errn_errp(datasets, parameter)

Estimate parameter asymmetric errors

Parameters

datasetsDatasets

Datasets

parameterParameter

For which parameter to get the value

Returns

resultdict

Dict with the parameter asymmetric errors. Entries are:

• parameter.name_errp : positive error on parameter value

• parameter.name_errn : negative error on parameter value

estimate_flux_point(datasets, energy_min, energy_max)

Estimate flux point for a single energy group.

Parameters

datasetsDatasets

Datasets

energy_min, energy_maxQuantity

Energy bounds to compute the flux point for.

Returns

resultdict

Dict with results for the flux point.

static estimate_npred(datasets)

Estimate npred for the flux point.

Parameters

datasetsDatasets

Datasets

Returns

resultdict

Dict with an array with one entry per dataset with the sum of the masked npred.

estimate_npred_excess(datasets)

Estimate npred excess for the source.

Parameters

datasetsDatasets

Datasets

Returns

resultdict

Dict with an array with one entry per dataset with the sum of the masked npred excess.

estimate_scan(datasets, parameter)

Estimate parameter stat scan.

Parameters

datasetsDatasets

The datasets used to estimate the model parameter

parameterParameter

For which parameter to get the value

Returns

resultdict

Dict with the parameter fit scan values. Entries are:

• parameter.name_scan : parameter values scan

• “stat_scan” : fit statistic values scan

estimate_time_bin_flux(datasets)

Estimate flux point for a single energy group.

Parameters

datasetsDatasets

List of dataset objects

Returns

resultFluxPoints

Resulting flux points.

estimate_ts(datasets, parameter)

Estimate parameter ts

Parameters

datasetsDatasets

Datasets

parameterParameter

For which parameter to get the value

Returns

resultdict

Dict with the TS of the best fit value compared to the null hypothesis. Entries are:

• “ts” : fit statistic difference with null hypothesis

• “npred” : predicted number of counts per dataset

estimate_ul(datasets, parameter)

Estimate parameter ul.

Parameters

datasetsDatasets

The datasets used to estimate the model parameter

parameterParameter

For which parameter to get the value

Returns

resultdict

Dict with the parameter ULs. Entries are:

• parameter.name_ul : upper limit on parameter value

static expand_map(m, dataset_names)

Expand map in dataset axis

Parameters

mapMap

Map to expand.

dataset_nameslist of str

Dataset names

Returns

mapMap

Expanded map.

get_scale_model(models)

Set scale model

Parameters

modelsModels

Models

Returns

modelScaleSpectralModel

Scale spectral model

run(datasets)

Run light curve extraction.

Normalize integral and energy flux between emin and emax.

Parameters

datasetslist of SpectrumDataset or MapDataset

Spectrum or Map datasets.

Returns

lightcurveFluxPoints

Light curve flux points