ParametricPSF

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

Bases: gammapy.irf.psf.core.PSF

Parametric PSF base class.

Parameters

axeslist of MapAxis or MapAxes

Axes.

datadict of ndarray or recarray

Data.

unitdict of str or Unit

Unit.

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, **kwargs)
evaluate_direct(rad, **kwargs)
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': 0.0}

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 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.

abstract evaluate_containment(rad, **kwargs)

abstract evaluate_direct(rad, **kwargs)

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.