TablePSF¶

class gammapy.irf.TablePSF(rad_axis, psf_value, interp_kwargs=None)[source]¶

Bases: object

Radially-symmetric table PSF.

Parameters

rad_axisQuantity with angle units: Offset wrt source position
psf_valueQuantity with sr^-1 units: PSF value array
interp_kwargsdict: Keyword arguments passed to ScaledRegularGridInterpolator

Attributes Summary

rad_axis

Methods Summary

`containment`(rad_max)	Compute PSF containment fraction.
`containment_radius`(fraction)	Containment radius.
`evaluate`(rad)	Evaluate PSF.
`from_shape`(shape, width, rad)	Make TablePSF objects with commonly used shapes.
`info`()	Print basic info.
`normalize`()	Normalize PSF to unit integral.
`plot_psf_vs_rad`([ax])	Plot PSF vs radius.

Attributes Documentation

rad_axis¶

Methods Documentation

containment(rad_max)[source]¶

Compute PSF containment fraction.

Parameters

rad_maxQuantity: Offset angle range

Returns

integralfloat: PSF integral

containment_radius(fraction)[source]¶

Containment radius.

Parameters

fractionarray_like: Containment fraction (range 0 .. 1)

Returns

radAngle: Containment radius angle

evaluate(rad)[source]¶

Evaluate PSF.

The following PSF quantities are available:

‘dp_domega’: PDF per 2-dim solid angle \(\Omega\) in sr^-1

\[\frac{dP}{d\Omega}\]

Parameters

radAngle: Offset wrt source position

Returns

psf_valueQuantity: PSF value

classmethod from_shape(shape, width, rad)[source]¶

Make TablePSF objects with commonly used shapes.

This function is mostly useful for examples and testing.

Parameters

shape{‘disk’, ‘gauss’}: PSF shape.
widthQuantity with angle units: PSF width angle (radius for disk, sigma for Gauss).
radQuantity with angle units: Offset angle

Returns

psfTablePSF: Table PSF

Examples

>>> import numpy as np
>>> from astropy.coordinates import Angle
>>> from gammapy.irf import TablePSF
>>> rad = Angle(np.linspace(0, 0.7, 100), 'deg')
>>> psf = TablePSF.from_shape(shape='gauss', width='0.2 deg', rad=rad)

info()[source]¶: Print basic info.

normalize()[source]¶

Normalize PSF to unit integral.

Computes the total PSF integral via the \(dP / dr\) spline and then divides the \(dP / dr\) array.

plot_psf_vs_rad(ax=None, **kwargs)[source]¶

Plot PSF vs radius.

Parameters

ax``
kwargsdict: Keyword arguments passed to matplotlib.pyplot.plot