PSFKing¶

class gammapy.irf.PSFKing(energy_lo, energy_hi, offset, gamma, sigma, energy_thresh_lo=<Quantity 0.1 TeV>, energy_thresh_hi=<Quantity 100. TeV>)[source]¶

Bases: object

King profile analytical PSF depending on energy and offset.

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

Parameters:	energy_lo : `Quantity` Lower energy boundary of the energy bin. energy_hi : `Quantity` Upper energy boundary of the energy bin. offset : `Angle` Offset nodes (1D) gamma : `ndarray` PSF parameter (2D) sigma : `Angle` PSF parameter (2D)

Methods Summary

`evaluate`([energy, offset])	Evaluate analytic PSF parameters at a given energy and offset.
`evaluate_direct`(r, gamma, sigma)	Evaluate the PSF model.
`from_table`(table)	Create `PSFKing` from `Table`.
`info`()	Print some basic info.
`read`(filename[, hdu])	Create `PSFKing` from FITS file.
`to_energy_dependent_table_psf`([theta, rad, …])	Convert to energy-dependent table PSF.
`to_fits`()	Convert PSF table data to FITS HDU list.
`write`(filename, args, *kwargs)	Write PSF to FITS file.

Methods Documentation

evaluate(energy=None, offset=None)[source]¶

Evaluate analytic PSF parameters at a given energy and offset.

Uses nearest-neighbor interpolation.

Parameters:	energy : `Quantity` energy value offset : `Angle` Offset in the field of view
Returns:	values : `Quantity` Interpolated value

static evaluate_direct(r, gamma, sigma)[source]¶

Evaluate the PSF model.

Formula is given here: PSF_KING.

Parameters:	r : `Angle` Offset from PSF center used for evaluating the PSF on a grid gamma : `Quantity` model parameter, no unit sigma : `Angle` model parameter
Returns:	psf_value : `Quantity` PSF value

classmethod from_table(table)[source]¶

Create PSFKing from Table.

Parameters:	table : `Table` Table King PSF info.

info()[source]¶: Print some basic info.

classmethod read(filename, hdu=1)[source]¶

Create PSFKing from FITS file.

Parameters:	filename : str File name

to_energy_dependent_table_psf(theta=None, rad=None, exposure=None)[source]¶

Convert to energy-dependent table PSF.

Parameters:	theta : `Angle` Offset in the field of view. Default theta = 0 deg rad : `Angle` Offset from PSF center used for evaluating the PSF on a grid. Default offset = [0, 0.005, …, 1.495, 1.5] deg. exposure : `Quantity` Energy dependent exposure. Should be in units equivalent to ‘cm^2 s’. Default exposure = 1.
Returns:	table_psf : `EnergyDependentTablePSF` Energy-dependent PSF

to_fits()[source]¶

Convert PSF table data to FITS HDU list.

Returns:	hdu_list : `HDUList` PSF in HDU list format.

write(filename, *args, **kwargs)[source]¶

Write PSF to FITS file.

Calls writeto, forwarding all arguments.