CountsSpectrum

class gammapy.spectrum.CountsSpectrum(energy_lo, energy_hi, data=None, interp_kwargs=None)

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)

Attributes Summary

default_interp_kwargs	Default interpolation kwargs
energy
total_counts	Total number of counts

Methods Summary

copy(self)	A deep copy of self.
energy_mask(self[, emin, emax])	Create a mask for a given energy range.
fill(self, events)	Fill with list of events.
from_hdulist(hdulist[, hdu1, hdu2])	Read OGIP format hdulist
peek(self[, figsize])	Quick-look summary plots.
plot(self[, ax, energy_unit, …])	Plot as data points.
plot_hist(self[, ax, energy_unit, show_energy])	Plot as histogram.
read(filename[, hdu1, hdu2])	Read from file.
rebin(self, parameter)	Rebin.
to_hdulist(self[, use_sherpa])	Convert to HDUList.
to_table(self)	Convert to Table.
write(self, filename[, use_sherpa])	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(self)

A deep copy of self.

energy_mask(self, emin=None, emax=None)

Create a mask for a given energy range.

Parameters:

emin, emax : Quantity

Energy range

fill(self, 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='COUNTS', hdu2='EBOUNDS')

Read OGIP format hdulist

peek(self, figsize=(5, 10))

Quick-look summary plots.

plot(self, 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(self, 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='COUNTS', hdu2='EBOUNDS')

Read from file.

rebin(self, parameter)

Rebin.

Parameters:

parameter : int

Number of bins to merge

Returns:

rebinned_spectrum : CountsSpectrum

Rebinned spectrum

to_hdulist(self, use_sherpa=False)

Convert to HDUList.

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

to_table(self)

Convert to Table.

Data format specification: PHA

write(self, filename, use_sherpa=False, **kwargs)

Write to file.