LightCurveEstimator¶

class gammapy.time.LightCurveEstimator(spec_extract)[source]¶

Light curve estimator.

For a usage example see light_curve.html.

Parameters:	spec_extract : `SpectrumExtraction` Contains statistics, IRF and event lists

Methods Summary

`compute_flux_point`(time_interval, …[, …])	Compute one flux point for one time interval.
`light_curve`(time_intervals, spectral_model, …)	Compute light curve.
`make_time_intervals_fixes`(time_step, …)	Create time intervals of fixed size.
`make_time_intervals_min_significance`(…[, …])	Create time intervals such that each bin of a light curve reach a given significance

Methods Documentation

compute_flux_point(time_interval, spectral_model, energy_range, ul_significance=3)[source]¶

Compute one flux point for one time interval.

Parameters:	time_interval : `Time` Time interval (2-element array, or a tuple of Time objects) spectral_model : `SpectralModel` Spectral model energy_range : `Quantity` True energy range to evaluate integrated flux (true energy) ul_significance : float Upper limit confidence level significance
Returns:	useinterval : bool Is True if the time_interval produce a valid flux point measurements : dict Dictionary with flux point measurement in the time interval

light_curve(time_intervals, spectral_model, energy_range, ul_significance=3)[source]¶

Compute light curve.

To be discussed: assumption that threshold energy in the same in reco and true energy.

Parameters:	time_intervals : list of `Time` List of time intervals spectral_model : `SpectralModel` Spectral model energy_range : `Quantity` True energy range to evaluate integrated flux (true energy) ul_significance : float Upper limit confidence level significance
Returns:	lc : `LightCurve` Light curve

static make_time_intervals_fixes(time_step, spectrum_extraction)[source]¶

Create time intervals of fixed size.

Parameters:	time_step : float Size of the light curve bins in seconds spectrum_extraction : `SpectrumExtraction` Contains statistics, IRF and event lists
Returns:	table : `Table` Table of time intervals

Examples

To extract intervals for light curve:

intervals = list(zip(table['t_start'], table['t_stop']))

make_time_intervals_min_significance(significance, significance_method, energy_range, spectrum_extraction, separators=None)[source]¶

Create time intervals such that each bin of a light curve reach a given significance

The function work event by event to create an interval containing enough statistic and then starting a new one

Parameters:

significance : float: Target significance for each light curve point
significance_method : {‘lima’, ‘simple’}: Significance method (see significance_on_off)
energy_range : Quantity: True energy range to evaluate integrated flux (true energy)
spectrum_extraction : SpectrumExtraction: Contains statistics, IRF and event lists
separators : list of Time: Contains a list of time to stop the current point creation (not saved) and start a new one Mostly useful between observations separated by a large time gap

Returns:

table : Table: Table of time intervals and information about their content : on/off events, alpha, significance

Examples

extract intervals for light curve :: intervals = list(zip(table[‘t_start’], table[‘t_stop’]))