PHACountsSpectrum¶

class gammapy.spectrum.PHACountsSpectrum(energy_lo, energy_hi, data=None, quality=None, backscal=None, areascal=None, is_bkg=False, obs_id=None, livetime=None, offset=None, meta=None)[source]¶

Bases: gammapy.spectrum.CountsSpectrum

Counts spectrum corresponding to OGIP PHA format.

The bkg flag controls whether the PHA counts spectrum represents a background estimate or not (this slightly affects the FITS header information when writing to disk).

Parameters:

energy_lo : Quantity

Lower bin edges of energy axis

energy_hi : Quantity

Upper bin edges of energy axis

data : array-like, optional

Counts

quality : int, array-like, optional

Mask bins in safe energy range (1 = bad, 0 = good)

backscal : float, array-like, optional

Background scaling factor

areascal : float, array-like, optional

Area scaling factor

is_bkg : bool, optional

Background or soure spectrum, default: False

obs_id : int

Observation identifier, optional

livetime : Quantity, optional

Observation livetime

offset : Quantity, optional

Field of view offset

meta : dict, optional

Meta information

Attributes Summary

`arffile`	ARF associated with the observation
`bins_in_safe_range`	Indices of bins within the energy thresholds
`bkgfile`	Background PHA files associated with the observation
`counts_in_safe_range`	Counts with bins outside safe range set to 0
`default_interp_kwargs`
`energy`
`hi_threshold`	High energy threshold of the observation (upper bin edge)
`lo_threshold`	Low energy threshold of the observation (lower bin edge)
`phafile`	PHA file associated with the observation
`quality`	Bins in safe energy range (1 = bad, 0 = good)
`rmffile`	RMF associated with the observation
`total_counts`	Total number of counts

Methods Summary

`copy`()	A deep copy of self.
`fill`(events)	Fill with list of events.
`from_hdulist`(hdulist[, hdu1, hdu2])	Create from `HDUList`.
`peek`([figsize])	Quick-look summary plots.
`plot`([ax, energy_unit, show_poisson_errors, …])	Plot as data points.
`plot_hist`([ax, energy_unit, show_energy])	Plot as histogram.
`read`(filename[, hdu1, hdu2])	Read from file.
`rebin`(parameter)	Rebin.
`reset_thresholds`()	Reset energy thresholds (i.e.
`to_hdulist`()	Convert to `HDUList`.
`to_sherpa`(name)	Convert to `sherpa.astro.data.DataPHA`.
`to_table`()	Convert to `Table`.
`write`(filename, **kwargs)	Write to file.

Attributes Documentation

arffile¶: ARF associated with the observation

bins_in_safe_range¶: Indices of bins within the energy thresholds

bkgfile¶: Background PHA files associated with the observation

counts_in_safe_range¶: Counts with bins outside safe range set to 0

default_interp_kwargs = {'bounds_error': False, 'method': 'nearest'}¶

energy¶

hi_threshold¶: High energy threshold of the observation (upper bin edge)

lo_threshold¶: Low energy threshold of the observation (lower bin edge)

phafile¶: PHA file associated with the observation

quality¶: Bins in safe energy range (1 = bad, 0 = good)

rmffile¶: RMF associated with the observation

total_counts¶: Total number of counts

Methods Documentation

copy()¶: A deep copy of self.

fill(events)¶

Fill with list of events.

TODO: Move to NDDataArray

Parameters:

events : Quantity, gammapy.data.EventList,

List of event energies

classmethod from_hdulist(hdulist, hdu1='SPECTRUM', hdu2='EBOUNDS')[source]¶: Create from HDUList.

peek(figsize=(5, 10))¶: Quick-look summary plots.

plot(ax=None, energy_unit='TeV', show_poisson_errors=False, show_energy=None, **kwargs)¶

Plot as data points.

kwargs are forwarded to errorbar

Parameters:

ax : axis (optional)

Axis instance to be used for the plot

energy_unit : str, Unit, optional

Unit of the energy axis

show_poisson_errors : bool, optional

Show poisson errors on the plot

show_energy : Quantity, optional

Show energy, e.g. threshold, as vertical line

Returns:

ax: axis

Axis instance used for the plot

plot_hist(ax=None, energy_unit='TeV', show_energy=None, **kwargs)¶

Plot as histogram.

kwargs are forwarded to hist

Parameters:

ax : axis (optional)

Axis instance to be used for the plot

energy_unit : str, Unit, optional

Unit of the energy axis

show_energy : Quantity, optional

Show energy, e.g. threshold, as vertical line

classmethod read(filename, hdu1='SPECTRUM', hdu2='EBOUNDS')[source]¶: Read from file.

rebin(parameter)[source]¶

Rebin.

See CountsSpectrum. This function treats the quality vector correctly

reset_thresholds()[source]¶: Reset energy thresholds (i.e. declare all energy bins valid)

to_hdulist()¶

Convert to HDUList.

This adds an EBOUNDS extension to the BinTableHDU produced by to_table, in order to store the energy axis

to_sherpa(name)[source]¶

Convert to sherpa.astro.data.DataPHA.

Parameters:

name : str

Instance name

to_table()[source]¶: Convert to Table.

write(filename, **kwargs)¶: Write to file.