EnergyDependentMultiGaussPSF#

class gammapy.irf.EnergyDependentMultiGaussPSF(axes, data=0, unit='', is_pointlike=False, fov_alignment=FoVAlignment.RADEC, meta=None, interp_kwargs=None)[source]#

Bases: gammapy.irf.psf.parametric.ParametricPSF

Triple Gauss analytical PSF depending on true energy and offset.

Parameters

axeslist of MapAxis: Required axes are [“energy_true”, “offset”].
datarecarray: Data array.
metadict: Metadata dictionary.

Examples

Plot R68 of the PSF vs. offset and true energy:

import matplotlib.pyplot as plt
from gammapy.irf import EnergyDependentMultiGaussPSF
filename = '$GAMMAPY_DATA/cta-1dc/caldb/data/cta/1dc/bcf/South_z20_50h/irf_file.fits'
psf = EnergyDependentMultiGaussPSF.read(filename, hdu='POINT SPREAD FUNCTION')
psf.plot_containment_radius(fraction=0.68)
plt.show()

(png, hires.png, pdf)

../_images/gammapy-irf-EnergyDependentMultiGaussPSF-1.png

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)	Containment of the PSF at given axes coordinates.
`evaluate_direct`(rad, **kwargs)	Evaluate 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': 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 = ['energy_true', 'offset']#

required_parameters = ['sigma_1', 'sigma_2', 'sigma_3', 'scale', 'ampl_2', 'ampl_3']#

tag = 'psf_3gauss'#

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, **kwargs)[source]#

Containment of the PSF at given axes coordinates.

Parameters

radQuantity: Rad value.
**kwargsdict: Parameters, see required_parameters.

Returns

containmentndarray: Containment.

static evaluate_direct(rad, **kwargs)[source]#

Evaluate PSF model.

Parameters

radQuantity: Rad value.
**kwargsdict: Parameters, see required_parameters.

Returns

valuendarray: 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.