PSFKing

class gammapy.irf.PSFKing(axes, data=0, unit='', is_pointlike=False, fov_alignment=FoVAlignment.RADEC, meta=None, interp_kwargs=None)

Bases: ParametricPSF

King profile analytical PSF depending on energy and offset.

This PSF parametrisation and FITS data format is described here: PSF_KING.

Parameters:

axeslist of MapAxis or MapAxes

Data axes, required are [“energy_true”, “offset”].

metadict

Metadata dictionary.

Attributes Summary

axes	MapAxes.
data
default_interp_kwargs
fov_alignment	Alignment of the field of view coordinate axes, see FoVAlignment.
has_offset_axis	Whether the IRF explicitly depends on offset.
is_pointlike	Whether the IRF is pointlike of full containment.
quantity	Quantity.
required_axes
required_parameters
tag
unit	Map unit as a Unit.

Methods Summary

containment(rad, **kwargs)	Containment of the PSF at given axes coordinates.
containment_radius(fraction[, factor])	Containment radius at given axes coordinates.
cumsum(axis_name)	Compute cumsum along a given axis.
evaluate(rad, **kwargs)	Evaluate the PSF model.
evaluate_containment(rad, gamma, sigma)	Containment of the PSF at given axes coordinates.
evaluate_direct(rad, gamma, sigma)	Evaluate the PSF model.
evaluate_parameters(energy_true, offset)	Evaluate analytic PSF parameters at a given energy and offset.
from_hdulist(hdulist[, hdu, format])	Create from HDUList.
from_table(table[, format])	Create parametric PSF from Table.
info([fraction, energy_true, offset])	Print PSF summary information.
integral(axis_name, **kwargs)	Compute integral along a given axis.
integrate_log_log(axis_name, **kwargs)	Integrate along a given axis.
interp_missing_data(axis_name)	Interpolate missing data along a given axis.
is_allclose(other[, rtol_axes, atol_axes])	Compare two data IRFs for equivalency.
normalize()	Normalize parametric PSF.
pad(pad_width, axis_name, **kwargs)	Pad IRF along a given axis.
peek([figsize])	Quick-look summary plots.
plot_containment_radius([ax, fraction, ...])	Plot containment image with energy and theta axes.
plot_containment_radius_vs_energy([ax, ...])	Plot containment fraction as a function of energy.
plot_psf_vs_rad([ax, offset, energy_true])	Plot PSF vs rad.
read(filename[, hdu, format])	Read from file.
slice_by_idx(slices)	Slice sub IRF from IRF object.
to_hdulist([format])	Write the HDU list.
to_psf3d([rad])	Create a PSF3D from a parametric PSF.
to_table([format])	Convert PSF table data to table.
to_table_hdu([format])	Convert to BinTableHDU.
to_unit(unit)	Convert IRF to unit.
write(filename, *args, **kwargs)	Write IRF to fits.

Attributes Documentation

axes

MapAxes.

data

default_interp_kwargs = {'bounds_error': False, 'fill_value': None}

fov_alignment

Alignment of the field of view coordinate axes, see FoVAlignment.

has_offset_axis

Whether the IRF explicitly depends on offset.

is_pointlike

Whether the IRF is pointlike of full containment.

quantity

Quantity.

required_axes = ['energy_true', 'offset']

required_parameters = ['gamma', 'sigma']

tag = 'psf_king'

unit

Map unit as a Unit.

Methods Documentation

containment(rad, **kwargs)

Containment of the PSF at given axes coordinates.

Parameters:

radQuantity

Rad value.

**kwargsdict

Other coordinates.

Returns:

containmentndarray

Containment.

containment_radius(fraction, factor=20, **kwargs)

Containment radius at given axes coordinates.

Parameters:

fractionfloat or ndarray

Containment fraction.

factorint, optional

Up-sampling factor of the rad axis, determines the precision of the computed containment radius. Default is 20.

**kwargsdict

Other coordinates.

Returns:

radiusAngle

Containment radius.

cumsum(axis_name)

Compute cumsum along a given axis.

Parameters:

axis_namestr

Along which axis to integrate.

Returns:

irfIRF

Cumsum IRF.

evaluate(rad, **kwargs)

Evaluate the PSF model.

Parameters:

radAngle

Offset from PSF center used for evaluating the PSF on a grid.

**kwargsdict

Other coordinates.

Returns:

psf_valueQuantity

PSF value.

static evaluate_containment(rad, gamma, sigma)

Containment of the PSF at given axes coordinates.

Parameters:

radQuantity

Rad value.

gammaQuantity

Gamma parameter.

sigmaQuantity

Sigma parameter.

Returns:

containmentndarray

Containment.

static evaluate_direct(rad, gamma, sigma)

Evaluate the PSF model.

Formula is given here: PSF_KING.

Parameters:

radAngle

Offset from PSF center used for evaluating the PSF on a grid.

Returns:

psf_valueQuantity

PSF value.

evaluate_parameters(energy_true, offset)

Evaluate analytic PSF parameters at a given energy and offset.

Uses nearest-neighbor interpolation.

Parameters:

energy_trueQuantity

Energy value.

offsetAngle

Offset in the field of view.

Returns:

valuesQuantity

Interpolated value.

classmethod from_hdulist(hdulist, hdu=None, format='gadf-dl3')

Create from HDUList.

Parameters:

hdulistHDUList

HDU list.

hdustr

HDU name.

format{“gadf-dl3”}

Format specification. Default is “gadf-dl3”.

Returns:

irfIRF

IRF class.

classmethod from_table(table, format='gadf-dl3')

Create parametric PSF from Table.

Parameters:

tableTable

Table information.

format{“gadf-dl3”}, optional

Format specification. Default is “gadf-dl3”.

Returns:

psfParametricPSF

PSF class.

info(fraction=(0.68, 0.95), energy_true=<Quantity [[ 1.],            [10.]] TeV>, offset=<Quantity 0. deg>)

Print PSF summary information.

The containment radius for given fraction, energies and thetas is computed and printed on the command line.

Parameters:

fractionlist, optional

Containment fraction to compute containment radius for, between 0 and 1. Default is (0.68, 0.95).

energy_trueQuantity, optional

Energies to compute containment radius for. Default is ([1.0], [10.0]) TeV.

offsetQuantity, optional

Offset to compute containment radius for. Default is 0 deg.

Returns:

infostring

Formatted string containing the summary information.

integral(axis_name, **kwargs)

Compute integral along a given axis.

This method uses interpolation of the cumulative sum.

Parameters:

axis_namestr

Along which axis to integrate.

**kwargsdict

Coordinates at which to evaluate the IRF.

Returns:

arrayQuantity

Returns 2D array with axes offset.

integrate_log_log(axis_name, **kwargs)

Integrate along a given axis.

This method uses log-log trapezoidal integration.

Parameters:

axis_namestr

Along which axis to integrate.

**kwargsdict

Coordinates at which to evaluate the IRF.

Returns:

arrayQuantity

Returns 2D array with axes offset.

interp_missing_data(axis_name)

Interpolate missing data along a given axis.

is_allclose(other, rtol_axes=0.001, atol_axes=1e-06, **kwargs)

Compare two data IRFs for equivalency.

Parameters:

othergammapy.irfs.ParametricPSF

The PSF to compare against.

rtol_axesfloat, optional

Relative tolerance for the axis comparison. Default is 1e-3.

atol_axesfloat, optional

Relative tolerance for the axis comparison. Default is 1e-6.

**kwargsdict

Keywords passed to numpy.allclose.

Returns:

is_allclosebool

Whether the IRF is all close.

normalize()

Normalize parametric PSF.

pad(pad_width, axis_name, **kwargs)

Pad IRF along a given axis.

Parameters:

pad_width{sequence, array_like, int}

Number of pixels padded to the edges of each axis.

axis_namestr

Axis to downsample. By default, spatial axes are padded.

**kwargsdict

Keyword argument forwarded to pad.

Returns:

irfIRF

Padded IRF.

peek(figsize=(15, 5))

Quick-look summary plots.

Parameters:

figsizetuple, optional

Size of the figure. Default is (15, 5).

plot_containment_radius(ax=None, fraction=0.68, add_cbar=True, axes_loc=None, kwargs_colorbar=None, **kwargs)

Plot containment image with energy and theta axes.

Parameters:

axAxes, optional

Matplotlib axes. Default is None.

fractionfloat, optional

Containment fraction between 0 and 1. Default is 0.68.

add_cbarbool, optional

Add a colorbar. Default is True.

axes_locdict, optional

Keyword arguments passed to append_axes.

kwargs_colorbardict, optional

Keyword arguments passed to colorbar.

**kwargsdict

Keyword arguments passed to pcolormesh.

Returns:

axAxes

Matplotlib axes.

plot_containment_radius_vs_energy(ax=None, fraction=(0.68, 0.95), offset=<Quantity [0., 1.] deg>, **kwargs)

Plot containment fraction as a function of energy.

Parameters:

axAxes, optional

Matplotlib axes. Default is None.

fractionlist of float or ndarray, optional

Containment fraction between 0 and 1. Default is (0.68, 0.95).

offsetQuantity, optional

Offset array. Default is (0, 1) deg.

**kwargsdict

Keyword arguments passed to plot.

Returns:

axAxes

Matplotlib axes.

plot_psf_vs_rad(ax=None, offset=<Quantity [0.] deg>, energy_true=<Quantity [ 0.1, 1., 10. ] TeV>, **kwargs)

Plot PSF vs rad.

Parameters:

axAxes, optional

Matplotlib axes. Default is None.

offsetAngle, optional

Offset in the field of view. Default is 0 deg.

energy_trueQuantity, optional

True energy at which to plot the profile. Default is [0.1, 1, 10] TeV.

kwargsdict

Keyword arguments.

classmethod read(filename, hdu=None, format='gadf-dl3')

Read from file.

Parameters:

filenamestr or Path

Filename.

hdustr

HDU name.

format{“gadf-dl3”}, optional

Format specification. Default is “gadf-dl3”.

Returns:

irfIRF

IRF class.

slice_by_idx(slices)

Slice sub IRF from IRF object.

Parameters:

slicesdict

Dictionary of axes names and slice object pairs. Contains one element for each non-spatial dimension. Axes not specified in the dictionary are kept unchanged.

Returns:

slicedIRF

Sliced IRF object.

to_hdulist(format='gadf-dl3')

Write the HDU list.

Parameters:

format{“gadf-dl3”}, optional

Format specification. Default is “gadf-dl3”.

to_psf3d(rad=None)

Create a PSF3D from a parametric PSF.

It will be defined on the same energy and offset values than the input PSF.

Parameters:

radQuantity

Rad values.

Returns:

psf3dPSF3D

3D PSF.

to_table(format='gadf-dl3')

Convert PSF table data to table.

Parameters:

format{“gadf-dl3”}

Format specification. Default is “gadf-dl3”.

Returns:

hdu_listHDUList

PSF in HDU list format.

to_table_hdu(format='gadf-dl3')

Convert to BinTableHDU.

Parameters:

format{“gadf-dl3”}, optional

Format specification. Default is “gadf-dl3”.

Returns:

hduBinTableHDU

IRF data table HDU.

to_unit(unit)

Convert IRF to unit.

write(filename, *args, **kwargs)

Write IRF to fits.

Calls writeto, forwarding all arguments.