CTA point spread function class with a King profile. More...

#include <GCTAPsfKing.hpp>

Inheritance diagram for GCTAPsfKing:

Public Member Functions
	GCTAPsfKing (void)
	Void constructor. More...

	GCTAPsfKing (const GFilename &filename)
	File constructor. More...

	GCTAPsfKing (const GCTAPsfKing &psf)
	Copy constructor. More...

virtual	~GCTAPsfKing (void)
	Destructor. More...

GCTAPsfKing &	operator= (const GCTAPsfKing &psf)
	Assignment operator. More...

double	operator() (const double &delta, const double &logE, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0, const bool &etrue=true) const
	Return point spread function (in units of sr^-1) More...

void	clear (void)
	Clear point spread function. More...

GCTAPsfKing *	clone (void) const
	Clone point spread functions. More...

std::string	classname (void) const
	Return class name. More...

void	load (const GFilename &filename)
	Load point spread function from FITS file. More...

GFilename	filename (void) const
	Return filename. More...

double	mc (GRan &ran, const double &logE, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0, const bool &etrue=true) const
	Simulate PSF offset (radians) More...

double	delta_max (const double &logE, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0, const bool &etrue=true) const
	Return maximum size of PSF (radians) More...

double	containment_radius (const double &fraction, const double &logE, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0, const bool &etrue=true) const
	Return the radius that contains a fraction of the events (radians) More...

std::string	print (const GChatter &chatter=NORMAL) const
	Print point spread function information. More...

const GCTAResponseTable &	table (void) const
	Return response table. More...

void	table (const GCTAResponseTable &table)
	Assign response table. More...

void	read (const GFitsTable &table)
	Read point spread function from FITS table. More...

void	write (GFitsBinTable &table) const
	Write point spread function into FITS table. More...

void	save (const GFilename &filename, const bool &clobber=false) const
	Save point spread function table into FITS file. More...

Public Member Functions inherited from GCTAPsf
	GCTAPsf (void)
	Void constructor. More...

	GCTAPsf (const GCTAPsf &psf)
	Copy constructor. More...

virtual	~GCTAPsf (void)
	Destructor. More...

GCTAPsf &	operator= (const GCTAPsf &psf)
	Assignment operator. More...

Public Member Functions inherited from GBase
virtual	~GBase (void)
	Destructor. More...

Private Member Functions
void	init_members (void)
	Initialise class members. More...

void	copy_members (const GCTAPsfKing &psf)
	Copy class members. More...

void	free_members (void)
	Delete class members. More...

void	update (const double &logE, const double &theta) const
	Update PSF parameter cache. More...

double	r_max (const double &logE, const double &theta) const
	Return maximum size of PSF (radians) More...

Private Attributes
GFilename	m_filename
	Name of Aeff response file. More...

GCTAResponseTable	m_psf
	PSF response table. More...

int	m_inx_energy
	Energy index. More...

int	m_inx_theta
	Theta index. More...

int	m_inx_gamma
	Gamma. More...

int	m_inx_sigma
	Sigma. More...

double	m_par_logE
	Cache energy. More...

double	m_par_theta
	Cache offset angle. More...

double	m_par_norm
	King profile normalization. More...

double	m_par_sigma
	King profile sigma (radians) More...

double	m_par_sigma2
	King profile sigma squared. More...

double	m_par_gamma
	King profile gamma parameter. More...

double	m_par_rmax
	Maximum PSF radius. More...

Additional Inherited Members
Protected Member Functions inherited from GCTAPsf
void	init_members (void)
	Initialise class members. More...

void	copy_members (const GCTAPsf &psf)
	Copy class members. More...

void	free_members (void)
	Delete class members. More...

Detailed Description

CTA point spread function class with a King profile.

This class implements the CTA point spread function response as function of energy as determined from a FITS table.

Definition at line 54 of file GCTAPsfKing.hpp.

Constructor & Destructor Documentation

GCTAPsfKing::GCTAPsfKing ( void )

Void constructor.

Constructs empty point spread function.

Definition at line 71 of file GCTAPsfKing.cpp.

References init_members().

Referenced by clone().

GCTAPsfKing::GCTAPsfKing ( const GFilename & filename )

explicit

File constructor.

Parameters

[in] filename PSF FITS file.

Constructs point spread function from a FITS file.

Definition at line 88 of file GCTAPsfKing.cpp.

References init_members(), and load().

GCTAPsfKing::GCTAPsfKing ( const GCTAPsfKing & psf )

Copy constructor.

Parameters

[in] psf Point spread function.

Constructs point spread function by copying from another point spread function.

Definition at line 109 of file GCTAPsfKing.cpp.

References copy_members(), and init_members().

GCTAPsfKing::~GCTAPsfKing ( void )

virtual

Destructor.

Destructs point spread function.

Definition at line 127 of file GCTAPsfKing.cpp.

References free_members().

Member Function Documentation

std::string GCTAPsfKing::classname ( void ) const

inlinevirtual

Return class name.

Returns: String containing the class name ("GCTAPsfKing").

Implements GCTAPsf.

Definition at line 145 of file GCTAPsfKing.hpp.

void GCTAPsfKing::clear ( void )

virtual

Clear point spread function.

Clears point spread function.

Implements GCTAPsf.

Definition at line 244 of file GCTAPsfKing.cpp.

References GCTAPsf::free_members(), free_members(), GCTAPsf::init_members(), and init_members().

GCTAPsfKing * GCTAPsfKing::clone ( void ) const

virtual

Clone point spread functions.

Returns: Deep copy of point spread function.

Returns a pointer to a deep copy of the point spread function.

Implements GCTAPsf.

Definition at line 266 of file GCTAPsfKing.cpp.

References GCTAPsfKing().

double GCTAPsfKing::containment_radius	(	const double &	fraction,
		const double &	logE,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`,
		const bool &	etrue = `true`
	)		const

virtual

Return the radius that contains a fraction of the events (radians)

Parameters

[in]	fraction	of events (0.0-1.0)
[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle in camera system (rad). Not used.
[in]	phi	Azimuth angle in camera system (rad). Not used.
[in]	zenith	Zenith angle in Earth system (rad). Not used.
[in]	azimuth	Azimuth angle in Earth system (rad). Not used.
[in]	etrue	Use true energy (true/false). Not used.

Returns: Containment radius (radians).

Exceptions

GException::invalid_argument Invalid fraction specified.

Calculate the radius from the center that contains 'fraction' percent of the events. fraction * 100. = Containment %. If the King profile parameters are invalid the method returns zero.

Implements GCTAPsf.

Definition at line 559 of file GCTAPsfKing.cpp.

References G_CONTAINMENT_RADIUS, m_par_gamma, m_par_norm, m_par_sigma, pow(), sqrt(), gammalib::str(), and update().

void GCTAPsfKing::copy_members ( const GCTAPsfKing & psf )

private

Copy class members.

Parameters

[in] psf Point spread function.

Definition at line 685 of file GCTAPsfKing.cpp.

References m_filename, m_inx_energy, m_inx_gamma, m_inx_sigma, m_inx_theta, m_par_gamma, m_par_logE, m_par_norm, m_par_rmax, m_par_sigma, m_par_sigma2, m_par_theta, and m_psf.

Referenced by GCTAPsfKing(), and operator=().

double GCTAPsfKing::delta_max	(	const double &	logE,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`,
		const bool &	etrue = `true`
	)		const

virtual

Return maximum size of PSF (radians)

Parameters

[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle in camera system (rad).
[in]	phi	Azimuth angle in camera system (rad). Not used.
[in]	zenith	Zenith angle in Earth system (rad). Not used.
[in]	azimuth	Azimuth angle in Earth system (rad). Not used.
[in]	etrue	Use true energy (true/false). Not used.

Determine the radius beyond which the PSF becomes negligible. This radius is set by this method to where the containment fraction become 99.9%. If the King profile parameters are invalid the method returns zero.

Implements GCTAPsf.

Definition at line 517 of file GCTAPsfKing.cpp.

References m_par_norm, r_max(), and update().

GFilename GCTAPsfKing::filename ( void ) const

inlinevirtual

Return filename.

Returns: Filename from which point spread function was loaded.

Returns filename from which point spread function was loaded.

Implements GCTAPsf.

Definition at line 159 of file GCTAPsfKing.hpp.

References m_filename.

Referenced by load().

void GCTAPsfKing::free_members ( void )

private

Delete class members.

Definition at line 710 of file GCTAPsfKing.cpp.

Referenced by clear(), operator=(), and ~GCTAPsfKing().

void GCTAPsfKing::init_members ( void )

private

Initialise class members.

Definition at line 658 of file GCTAPsfKing.cpp.

References GCTAResponseTable::clear(), GFilename::clear(), m_filename, m_inx_energy, m_inx_gamma, m_inx_sigma, m_inx_theta, m_par_gamma, m_par_logE, m_par_norm, m_par_rmax, m_par_sigma, m_par_sigma2, m_par_theta, and m_psf.

Referenced by clear(), GCTAPsfKing(), and operator=().

void GCTAPsfKing::load ( const GFilename & filename )

virtual

Load point spread function from FITS file.

Parameters

[in] filename FITS file name.

Loads the point spread function from a FITS file.

If no extension name is given the method scans the HDUCLASS keywords of all extensions and loads the background from the first extension for which HDUCLAS4=PSF_KING.

Otherwise, the background will be loaded from the POINT SPREAD FUNCTION extension.

Implements GCTAPsf.

Definition at line 372 of file GCTAPsfKing.cpp.

References GFits::close(), GFilename::extname(), gammalib::extname_cta_psfking, filename(), gammalib::gadf_hduclas4(), m_filename, read(), GFits::table(), and table().

Referenced by GCTAPsfKing().

double GCTAPsfKing::mc	(	GRan &	ran,
		const double &	logE,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`,
		const bool &	etrue = `true`
	)		const

virtual

Simulate PSF offset (radians)

Parameters

[in]	ran	Random number generator.
[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle in camera system (rad).
[in]	phi	Azimuth angle in camera system (rad). Not used.
[in]	zenith	Zenith angle in Earth system (rad). Not used.
[in]	azimuth	Azimuth angle in Earth system (rad). Not used.
[in]	etrue	Use true energy (true/false). Not used.

Draws a random offset angle for the King Profile. If the King profile parameters are invalid the method returns a zero offset angle.

Implements GCTAPsf.

Definition at line 464 of file GCTAPsfKing.cpp.

References m_par_gamma, m_par_norm, m_par_rmax, m_par_sigma, pow(), sqrt(), GRan::uniform(), and update().

double GCTAPsfKing::operator()	(	const double &	delta,
		const double &	logE,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`,
		const bool &	etrue = `true`
	)		const

virtual

Return point spread function (in units of sr^-1)

Parameters

[in]	delta	Angular separation between true and measured photon directions (rad).
[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle in camera system (rad).
[in]	phi	Azimuth angle in camera system (rad). Not used.
[in]	zenith	Zenith angle in Earth system (rad). Not used.
[in]	azimuth	Azimuth angle in Earth system (rad). Not used.
[in]	etrue	Use true energy (true/false). Not used.

Returns the point spread function for a given angular separation in units of sr^-1 for a given energy. If the King profile parameters are invalid the method returns zero.

Implements GCTAPsf.

Definition at line 191 of file GCTAPsfKing.cpp.

References m_par_gamma, m_par_norm, m_par_rmax, m_par_sigma, pow(), and update().

GCTAPsfKing & GCTAPsfKing::operator= ( const GCTAPsfKing & psf )

Assignment operator.

Parameters

[in] psf Point spread function.

Returns: Point spread function.

Assigns point spread function.

Definition at line 151 of file GCTAPsfKing.cpp.

References copy_members(), free_members(), init_members(), and GCTAPsf::operator=().

std::string GCTAPsfKing::print ( const GChatter & chatter = NORMAL ) const

virtual

Print point spread function information.

Parameters

[in] chatter Chattiness.

Returns: String containing point spread function information.

Implements GCTAPsf.

Definition at line 602 of file GCTAPsfKing.cpp.

References GCTAResponseTable::axes(), GCTAResponseTable::axis_bins(), GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), m_filename, m_inx_energy, m_inx_theta, m_psf, gammalib::parformat(), SILENT, and gammalib::str().

double GCTAPsfKing::r_max	(	const double &	logE,
		const double &	theta
	)		const

private

Return maximum size of PSF (radians)

Parameters

[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle in camera system (radians).

Returns: Maximum size of point spread function (radians).

Determine the radius beyond which the PSF becomes negligible. This radius is set by this method to where the containment fraction become 99.9%.

This method requires the m_par_gamma and m_par_sigma to be set to valid values. In case that the parameters lead to an infinite result the method will return a maximum size of zero.

Definition at line 813 of file GCTAPsfKing.cpp.

References gammalib::is_infinite(), m_par_gamma, m_par_sigma, pow(), and sqrt().

Referenced by delta_max(), and update().

void GCTAPsfKing::read ( const GFitsTable & table )

Read point spread function from FITS table.

Parameters

[in] table FITS table.

Exceptions

GException::invalid_value Response table is not two-dimensional.

Reads the point spread function form the FITS table. The following column names are mandatory:

ENERG_LO - Energy lower bin boundaries
ENERG_HI - Energy upper bin boundaries
THETA_LO - Offset angle lower bin boundaries
THETA_HI - Offset angle upper bin boundaries
GAMMA    - Gamma
SIGMA    - Sigma

The data are stored in the m_psf member. The energy axis will be set to log10, the offset angle axis to radians.

Definition at line 293 of file GCTAPsfKing.cpp.

References GCTAResponseTable::axes(), GCTAResponseTable::axis(), GCTAResponseTable::axis_log10(), GCTAResponseTable::axis_radians(), GCTAResponseTable::clear(), gammalib::deg2rad, G_READ, m_inx_energy, m_inx_gamma, m_inx_sigma, m_inx_theta, m_psf, GCTAResponseTable::read(), GCTAResponseTable::scale(), gammalib::str(), and GCTAResponseTable::table().

Referenced by load().

void GCTAPsfKing::save	(	const GFilename &	filename,
		const bool &	clobber = `false`
	)		const

Save point spread function table into FITS file.

Parameters

[in]	filename	FITS file name.
[in]	clobber	Overwrite existing file?

Saves point spread function into a FITS file. If a file with the given filename does not yet exist it will be created, otherwise the method opens the existing file. The method will create a (or replace an existing) point spread function extension. The extension name can be specified as part of the filename, or if no extension name is given, is assumed to be POINT SPREAD FUNCTION.

An existing file will only be modified if the clobber flag is set to true.

Definition at line 416 of file GCTAPsfKing.cpp.

References GFitsHDU::extname(), GFilename::extname(), gammalib::extname_cta_psfking, GFits::remove(), table(), GFilename::url(), and write().

const GCTAResponseTable & GCTAPsfKing::table ( void ) const

inline

Return response table.

Returns: Response table.

Definition at line 170 of file GCTAPsfKing.hpp.

References m_psf.

Referenced by load(), save(), and table().

void GCTAPsfKing::table ( const GCTAResponseTable & table )

inline

Assign response table.

Parameters

[in] table Response table.

Definition at line 181 of file GCTAPsfKing.hpp.

References m_psf, and table().

void GCTAPsfKing::update	(	const double &	logE,
		const double &	theta
	)		const

private

Update PSF parameter cache.

Parameters

[in]	logE	Log10 of the true photon energy (TeV).
[in]	theta	Offset angle.

This method updates the PSF parameter cache. As the performance table PSF only depends on energy, the only parameter on which the cache values depend is the energy. If the PSF parameters are invalid the m_par_norm member will be set to zero. Valid PSF parameters are \(\gamma > 1\) and \(\sigma > 0\).

Definition at line 729 of file GCTAPsfKing.cpp.

References gammalib::deg2rad, m_inx_energy, m_inx_gamma, m_inx_sigma, m_par_gamma, m_par_logE, m_par_norm, m_par_rmax, m_par_sigma, m_par_sigma2, m_par_theta, m_psf, norm(), pow(), r_max(), and gammalib::twopi.