CountsSpectrum¶

class gammapy.spectrum.CountsSpectrum(energy_lo, energy_hi, data=None, interp_kwargs=None)[source]¶

Bases: object

Generic counts spectrum.

Parameters:

energy_lo : Quantity

Lower bin edges of energy axis

energy_hi : Quantity

Upper bin edges of energy axis

data : Quantity, array-like

Counts

Examples

from gammapy.spectrum import CountsSpectrum
import numpy as np
import astropy.units as u

ebounds = np.logspace(0,1,11) * u.TeV
data = np.arange(10)
spec = CountsSpectrum(
    energy_lo=ebounds[:-1],
    energy_hi=ebounds[1:],
    data=data,
)
spec.plot(show_poisson_errors=True)

(png, hires.png, pdf)

../_images/gammapy-spectrum-CountsSpectrum-1.png

Attributes Summary

`default_interp_kwargs`	Default interpolation kwargs
`energy`
`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])	Read OGIP format 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.
`to_hdulist`()	Convert to `HDUList`.
`to_table`()	Convert to `Table`.
`write`(filename, **kwargs)	Write to file.

Attributes Documentation

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

energy¶

total_counts¶: Total number of counts

Methods Documentation

copy()[source]¶: A deep copy of self.

fill(events)[source]¶

Fill with list of events.

TODO: Move to NDDataArray

Parameters:

events : Quantity, gammapy.data.EventList,

List of event energies

classmethod from_hdulist(hdulist, hdu1='COUNTS', hdu2='EBOUNDS')[source]¶: Read OGIP format hdulist

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

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

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)[source]¶

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='COUNTS', hdu2='EBOUNDS')[source]¶: Read from file.

rebin(parameter)[source]¶

Rebin.

Parameters:

parameter : int

Number of bins to merge

Returns:

rebinned_spectrum : CountsSpectrum

Rebinned spectrum

to_hdulist()[source]¶

Convert to HDUList.

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

to_table()[source]¶

Convert to Table.

Data format specification: PHA

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