EDispKernel¶
-
class
gammapy.irf.
EDispKernel
(e_true_lo, e_true_hi, e_reco_lo, e_reco_hi, data, interp_kwargs=None, meta=None)[source]¶ Bases:
object
Energy dispersion matrix.
Data format specification: RMF
- Parameters
See also
Examples
Create a Gaussian energy dispersion matrix:
import numpy as np import astropy.units as u from gammapy.irf import EDispKernel energy = np.logspace(0, 1, 101) * u.TeV edisp = EDispKernel.from_gauss( e_true=energy, e_reco=energy, sigma=0.1, bias=0, )
Have a quick look:
>>> print(edisp) >>> edisp.peek()
Attributes Summary
Default Interpolation kwargs for
NDDataArray
.Reconstructed energy axis (
MapAxis
)True energy axis (
MapAxis
)Energy dispersion PDF matrix (
ndarray
).Methods Summary
from_diagonal_response
(e_true[, e_reco])Create energy dispersion from a diagonal response, i.e.
from_gauss
(e_true, e_reco, sigma, bias[, …])Create Gaussian energy dispersion matrix (
EnergyDispersion
).from_hdulist
(hdulist[, hdu1, hdu2])Create
EnergyDispersion
object fromHDUList
.get_bias
(self, e_true)Get reconstruction bias for a given true energy.
get_bias_energy
(self, bias[, emin, emax])Find energy corresponding to a given bias.
get_mean
(self, e_true)Get mean reconstructed energy for a given true energy.
get_resolution
(self, e_true)Get energy resolution for a given true energy.
pdf_in_safe_range
(self, lo_threshold, …)PDF matrix with bins outside threshold set to 0.
peek
(self[, figsize])Quick-look summary plot.
plot_bias
(self[, ax])Plot reconstruction bias.
plot_matrix
(self[, ax, show_energy, add_cbar])Plot PDF matrix.
read
(filename[, hdu1, hdu2])Read from file.
to_hdulist
(self[, use_sherpa])Convert RMF to FITS HDU list format.
to_table
(self)Convert to
Table
.write
(self, filename[, use_sherpa])Write to file.
Attributes Documentation
-
default_interp_kwargs
= {'bounds_error': False, 'fill_value': 0, 'method': 'nearest'}¶ Default Interpolation kwargs for
NDDataArray
. Fill zeros and do not interpolate
-
pdf_matrix
¶ Energy dispersion PDF matrix (
ndarray
).Rows (first index): True Energy Columns (second index): Reco Energy
Methods Documentation
-
classmethod
from_diagonal_response
(e_true, e_reco=None)[source]¶ Create energy dispersion from a diagonal response, i.e. perfect energy resolution
This creates the matrix corresponding to a perfect energy response. It contains ones where the e_true center is inside the e_reco bin. It is a square diagonal matrix if e_true = e_reco.
This is useful in cases where code always applies an edisp, but you don’t want it to do anything.
- Parameters
- e_true, e_reco
Quantity
Energy bounds for true and reconstructed energy axis
- e_true, e_reco
Examples
If
e_true
equalse_reco
, you get a diagonal matrix:e_true = [0.5, 1, 2, 4, 6] * u.TeV edisp = EnergyDispersion.from_diagonal_response(e_true) edisp.plot_matrix()
Example with different energy binnings:
e_true = [0.5, 1, 2, 4, 6] * u.TeV e_reco = [2, 4, 6] * u.TeV edisp = EnergyDispersion.from_diagonal_response(e_true, e_reco) edisp.plot_matrix()
-
classmethod
from_gauss
(e_true, e_reco, sigma, bias, pdf_threshold=1e-06)[source]¶ Create Gaussian energy dispersion matrix (
EnergyDispersion
).
-
classmethod
from_hdulist
(hdulist, hdu1='MATRIX', hdu2='EBOUNDS')[source]¶ Create
EnergyDispersion
object fromHDUList
.- Parameters
- hdulist
HDUList
HDU list with
MATRIX
andEBOUNDS
extensions.- hdu1str, optional
HDU containing the energy dispersion matrix, default: MATRIX
- hdu2str, optional
HDU containing the energy axis information, default, EBOUNDS
- hdulist
-
get_bias
(self, e_true)[source]¶ Get reconstruction bias for a given true energy.
Bias is defined as
\[\frac{E_{reco}-E_{true}}{E_{true}}\]- Parameters
- e_true
Quantity
True energy
- e_true
-
get_bias_energy
(self, bias, emin=None, emax=None)[source]¶ Find energy corresponding to a given bias.
In case the solution is not unique, provide the
emin
oremax
arguments to limit the solution to the given range. By default the peak energy of the bias is chosen asemin
.
-
get_resolution
(self, e_true)[source]¶ Get energy resolution for a given true energy.
The resolution is given as a percentage of the true energy
- Parameters
- e_true
Quantity
True energy
- e_true
-
pdf_in_safe_range
(self, lo_threshold, hi_threshold)[source]¶ PDF matrix with bins outside threshold set to 0.
-
plot_bias
(self, ax=None, **kwargs)[source]¶ Plot reconstruction bias.
See
get_bias
method.- Parameters
- ax
Axes
, optional Axis
- ax
-
classmethod
read
(filename, hdu1='MATRIX', hdu2='EBOUNDS')[source]¶ Read from file.
- Parameters
- filename
pathlib.Path
, str File to read
- hdu1str, optional
HDU containing the energy dispersion matrix, default: MATRIX
- hdu2str, optional
HDU containing the energy axis information, default, EBOUNDS
- filename
-
to_hdulist
(self, use_sherpa=False, **kwargs)[source]¶ Convert RMF to FITS HDU list format.
- Parameters
- header
Header
Header to be written in the fits file.
- energy_unitstr
Unit in which the energy is written in the HDU list
- header
- Returns
- hdulist
HDUList
RMF in HDU list format.
- hdulist
Notes
For more info on the RMF FITS file format see: https://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/summary/cal_gen_92_002_summary.html
-
to_table
(self)[source]¶ Convert to
Table
.The output table is in the OGIP RMF format. https://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/memos/cal_gen_92_002/cal_gen_92_002.html#Tab:1