CTA 3D background class. More...

#include <GCTABackground3D.hpp>

Inheritance diagram for GCTABackground3D:

Public Member Functions
	GCTABackground3D (void)
	Void constructor. More...

	GCTABackground3D (const GFilename &filename)
	File constructor. More...

	GCTABackground3D (const GCTABackground3D &bgd)
	Copy constructor. More...

virtual	~GCTABackground3D (void)
	Destructor. More...

virtual double	operator() (const double &logE, const double &detx, const double &dety) const
	Return background rate in units of events MeV \(^{-1}\) s \(^{-1}\) sr \(^{-1}\). More...

GCTABackground3D &	operator= (const GCTABackground3D &bgd)
	Assignment operator. More...

void	clear (void)
	Clear background. More...

GCTABackground3D *	clone (void) const
	Clone background. More...

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

void	load (const GFilename &filename)
	Load background from FITS file. More...

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

GCTAInstDir	mc (const GEnergy &energy, const GTime &time, GRan &ran) const
	Returns MC instrument direction. More...

const GModelSpectralNodes &	spectrum (void) const
	Get response cube spectrum. More...

double	rate_ebin (const GCTAInstDir &dir, const GEnergy &emin, const GEnergy &emax) const
	Returns background rate integrated over energy interval in units of events s \(^{-1}\) sr \(^{-1}\). More...

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

bool	is_valid (void) const
	Return validity of background model. 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 background from FITS table. More...

void	write (GFitsBinTable &table) const
	Write background into FITS table. More...

void	save (const GFilename &filename, const bool &clobber=false) const
	Save background into FITS file. More...

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

	GCTABackground (const GCTABackground &bgd)
	Copy constructor. More...

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

GCTABackground &	operator= (const GCTABackground &bgd)
	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 GCTABackground3D &bgd)
	Copy class members. More...

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

void	set_members (void)
	Set members from background table. More...

int	index (const int &idetx, const int &idety, const int &iebin) const
	Return background rate bin index. More...

void	init_mc_cache (void) const
	Initialise Monte Carlo cache. More...

void	init_mc_max_rate (void) const
	Initialise array of maximum background rate. More...

double	solid_angle (const double &detx1, const double &dety1, const double &detx2, const double &dety2, const double &detx3, const double &dety3) const
	Compute solid angle of pixel wedge. More...

double	rate (const int &iebin, const double &detx, const double &dety) const
	Return background rate for a given energy bin and DETX-DETY value (events/s/MeV/sr) More...

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

GCTAResponseTable	m_background
	Background response table. More...

GEnergies	m_energy
	Vector of energies. More...

int	m_inx_detx
	DETX index. More...

int	m_inx_dety
	DETY index. More...

int	m_inx_energy
	Energy index. More...

int	m_inx_bgd
	Background index. More...

int	m_num_detx
	Number of DETX bins. More...

int	m_num_dety
	Number of DETY bins. More...

int	m_num_energy
	Number of energy bins. More...

int	m_num [3]
	Array of number of bins. More...

double	m_detx_min
	DETX minimum (radians) More...

double	m_detx_max
	DETX maximum (radians) More...

double	m_dety_min
	DETY minimum (radians) More...

double	m_dety_max
	DETY maximum (radians) More...

double	m_logE_min
	Log10(E/TeV) minimum. More...

double	m_logE_max
	Log10(E/TeV) maximum. More...

std::vector< double >	m_mc_max
	Maximum background rate. More...

GModelSpectralNodes	m_mc_spectrum
	Response cube spectrum. More...

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

void	copy_members (const GCTABackground &bgd)
	Copy class members. More...

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

Detailed Description

CTA 3D background class.

Definition at line 53 of file GCTABackground3D.hpp.

Constructor & Destructor Documentation

GCTABackground3D::GCTABackground3D ( void )

Void constructor.

Constructs empty background.

Definition at line 69 of file GCTABackground3D.cpp.

References init_members().

Referenced by clone().

GCTABackground3D::GCTABackground3D ( const GFilename & filename )

explicit

File constructor.

Parameters

[in] filename FITS file name.

Constructs background from a FITS file.

Definition at line 86 of file GCTABackground3D.cpp.

References init_members(), and load().

GCTABackground3D::GCTABackground3D ( const GCTABackground3D & bgd )

Copy constructor.

Parameters

[in] bgd Background.

Constructs background by copying from another background.

Definition at line 107 of file GCTABackground3D.cpp.

References copy_members(), and init_members().

GCTABackground3D::~GCTABackground3D ( void )

virtual

Destructor.

Destructs background.

Definition at line 126 of file GCTABackground3D.cpp.

References free_members().

Member Function Documentation

std::string GCTABackground3D::classname ( void ) const

inlinevirtual

Return class name.

Returns: String containing the class name ("GCTABackground3D").

Implements GCTABackground.

Definition at line 139 of file GCTABackground3D.hpp.

void GCTABackground3D::clear ( void )

virtual

Clear background.

Clears background.

Implements GCTABackground.

Definition at line 246 of file GCTABackground3D.cpp.

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

GCTABackground3D * GCTABackground3D::clone ( void ) const

virtual

Clone background.

Returns: Deep copy of background.

Returns a pointer to a deep copy of the background.

Implements GCTABackground.

Definition at line 268 of file GCTABackground3D.cpp.

References GCTABackground3D().

void GCTABackground3D::copy_members ( const GCTABackground3D & bgd )

private

Copy class members.

Parameters

[in] bgd Background.

Definition at line 763 of file GCTABackground3D.cpp.

References m_background, m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_energy, m_filename, m_inx_bgd, m_inx_detx, m_inx_dety, m_inx_energy, m_logE_max, m_logE_min, m_mc_max, m_mc_spectrum, m_num, m_num_detx, m_num_dety, and m_num_energy.

Referenced by GCTABackground3D(), and operator=().

GFilename GCTABackground3D::filename ( void ) const

inlinevirtual

Return filename.

Returns: Returns filename from which the background was loaded.

Implements GCTABackground.

Definition at line 151 of file GCTABackground3D.hpp.

References m_filename.

Referenced by load().

void GCTABackground3D::free_members ( void )

private

Delete class members.

Definition at line 798 of file GCTABackground3D.cpp.

Referenced by clear(), operator=(), and ~GCTABackground3D().

int GCTABackground3D::index	(	const int &	idetx,
		const int &	idety,
		const int &	iebin
	)		const

private

Return background rate bin index.

Parameters

[in]	idetx	DETX index.
[in]	idety	DETY index.
[in]	iebin	Energy index.

Returns: Background rate bin index.

Returns the background rate bin index independent of the ordering.

Definition at line 900 of file GCTABackground3D.cpp.

References m_inx_detx, m_inx_dety, m_inx_energy, and m_num.

Referenced by init_mc_max_rate(), and rate().

void GCTABackground3D::init_mc_cache ( void ) const

private

Initialise Monte Carlo cache.

Exceptions

GException::invalid_value Background response table was empty.

Initialises the cache for Monte Carlo sampling.

Definition at line 926 of file GCTABackground3D.cpp.

References GModelSpectralNodes::append(), GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_hi_unit(), GCTAResponseTable::axis_lo(), GCTAResponseTable::axis_lo_unit(), GModelSpectralNodes::clear(), GEnergies::extend(), G_INIT_MC_CACHE, init_mc_max_rate(), m_background, m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_energy, m_inx_energy, m_mc_max, m_mc_spectrum, m_num_detx, m_num_dety, m_num_energy, GModelSpectralNodes::nodes(), GEnergies::remove(), GEnergies::size(), and solid_angle().

Referenced by mc(), and spectrum().

void GCTABackground3D::init_mc_max_rate ( void ) const

private

Initialise array of maximum background rate.

Initialises the array m_mc_max that holds the maximum background rate in each DETX-DETY plane of the background model.

Definition at line 1069 of file GCTABackground3D.cpp.

References index(), m_background, m_inx_bgd, m_mc_max, m_num_detx, m_num_dety, m_num_energy, and rate().

Referenced by init_mc_cache().

void GCTABackground3D::init_members ( void )

private

Initialise class members.

Definition at line 726 of file GCTABackground3D.cpp.

References GCTAResponseTable::clear(), GEnergies::clear(), GFilename::clear(), GModelSpectralNodes::clear(), m_background, m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_energy, m_filename, m_inx_bgd, m_inx_detx, m_inx_dety, m_inx_energy, m_logE_max, m_logE_min, m_mc_max, m_mc_spectrum, m_num, m_num_detx, m_num_dety, and m_num_energy.

Referenced by clear(), GCTABackground3D(), and operator=().

bool GCTABackground3D::is_valid ( void ) const

inline

Return validity of background model.

Returns: True if background model is valid.

Definition at line 181 of file GCTABackground3D.hpp.

References GCTAResponseTable::axes(), and m_background.

Referenced by operator()(), print(), and rate_ebin().

void GCTABackground3D::load ( const GFilename & filename )

virtual

Load background from FITS file.

Parameters

[in] filename FITS file name.

Loads the background 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=BKG_3D.

Otherwise, the background will be loaded from the BACKGROUND extension.

Implements GCTABackground.

Definition at line 365 of file GCTABackground3D.cpp.

References GFits::close(), GFilename::extname(), gammalib::extname_cta_background3d, filename(), gammalib::gadf_hduclas4(), m_filename, read(), table(), and GFits::table().

Referenced by GCTABackground3D().

GCTAInstDir GCTABackground3D::mc	(	const GEnergy &	energy,
		const GTime &	time,
		GRan &	ran
	)		const

virtual

Returns MC instrument direction.

Parameters

[in]	energy	Event energy.
[in]	time	Event trigger time.
[in,out]	ran	Random number generator.

Returns: CTA instrument direction.

Returns a Monte Carlo simulated instrument direction for a given energy and event trigger time. The simulation is done using a rejection method that makes use of the background rate access operator. This assures that the simulation is consistent with the background rate interpolation that is done by the access operator.

Implements GCTABackground.

Definition at line 458 of file GCTABackground3D.cpp.

References GCTAResponseTable::axis_nodes(), GCTAInstDir::detx(), GCTAInstDir::dety(), GModelSpectralNodes::energy(), G_MC, init_mc_cache(), GNodeArray::inx_left(), GNodeArray::inx_right(), GEnergy::log10TeV(), m_background, m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_inx_energy, m_mc_max, m_mc_spectrum, GModelSpectralNodes::nodes(), operator()(), GEnergy::print(), gammalib::rad2deg, GNodeArray::set_value(), gammalib::str(), GRan::uniform(), and gammalib::warning().

double GCTABackground3D::operator()	(	const double &	logE,
		const double &	detx,
		const double &	dety
	)		const

virtual

Return background rate in units of events MeV \(^{-1}\) s \(^{-1}\) sr \(^{-1}\).

Parameters

[in]	logE	Log10 of the true photon energy (TeV).
[in]	detx	Tangential X coordinate in nominal system (radians).
[in]	dety	Tangential Y coordinate in nominal system (radians).

Returns: Background rate (events MeV \(^{-1}\) s \(^{-1}\) sr \(^{-1}\)).

Returns the background rate for a given energy and detector coordinates. The rate is given per ontime. The operator interpolates linearly in DETX and DETY, and logarithmically in energy.

The operator assures that the background rate never becomes negative. For invalid background models or detector coordinates outside the range covered by the response cube, the operator returns a rate of zero.

Implements GCTABackground.

Definition at line 191 of file GCTABackground3D.cpp.

References GCTAResponseTable::axis_nodes(), exp(), GNodeArray::inx_left(), GNodeArray::inx_right(), is_valid(), log(), m_background, m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_inx_energy, rate(), GNodeArray::set_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

Referenced by mc().

GCTABackground3D & GCTABackground3D::operator= ( const GCTABackground3D & bgd )

Assignment operator.

Parameters

[in] bgd Background.

Returns: Background.

Assigns background.

Definition at line 150 of file GCTABackground3D.cpp.

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

std::string GCTABackground3D::print ( const GChatter & chatter = NORMAL ) const

virtual

Print background information.

Parameters

[in] chatter Chattiness.

Returns: String containing background information.

Implements GCTABackground.

Definition at line 655 of file GCTABackground3D.cpp.

References GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), is_valid(), m_background, m_filename, m_inx_detx, m_inx_dety, m_inx_energy, m_num_detx, m_num_dety, m_num_energy, gammalib::parformat(), SILENT, and gammalib::str().

double GCTABackground3D::rate	(	const int &	iebin,
		const double &	detx,
		const double &	dety
	)		const

private

Return background rate for a given energy bin and DETX-DETY value (events/s/MeV/sr)

Parameters

[in]	iebin	Energy index.
[in]	detx	Tangential X coordinate in nominal system (radians).
[in]	dety	Tangential Y coordinate in nominal system (radians).

Returns: Background rate (events/s/MeV/sr)

Definition at line 1185 of file GCTABackground3D.cpp.

References GCTAResponseTable::axis_nodes(), index(), GNodeArray::inx_left(), GNodeArray::inx_right(), m_background, m_inx_bgd, m_inx_detx, m_inx_dety, GNodeArray::set_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

Referenced by init_mc_max_rate(), operator()(), and rate_ebin().

double GCTABackground3D::rate_ebin	(	const GCTAInstDir &	dir,
		const GEnergy &	emin,
		const GEnergy &	emax
	)		const

virtual

Returns background rate integrated over energy interval in units of events s \(^{-1}\) sr \(^{-1}\).

Parameters

[in]	dir	Instrument direction.
[in]	emin	Minimum energy of energy interval.
[in]	emax	Maximum energy of energy interval.

Returns: Integrated background count rate (events s \(^{-1}\) sr \(^{-1}\)).

Returns the background count rate for a given instrument direction that is integrated over a specified energy interval. The rate is given per ontime.

If the energy interval is not positive, a zero background rate is returned.

Implements GCTABackground.

Definition at line 574 of file GCTABackground3D.cpp.

References GCTAInstDir::detx(), GCTAInstDir::dety(), is_valid(), GEnergy::log10TeV(), m_detx_max, m_detx_min, m_dety_max, m_dety_min, m_energy, GEnergy::MeV(), gammalib::plaw_integral(), rate(), and GEnergies::size().

void GCTABackground3D::read ( const GFitsTable & table )

Read background from FITS table.

Parameters

[in] table FITS table.

Reads the background form the FITS table. The following column names are mandatory:

DETX_LO  - DETX lower bin boundaries
DETX_HI  - DETX upper bin boundaries
DETY_LO  - DETY lower bin boundaries
DETY_HI  - DETY upper bin boundaries
ENERG_LO - Energy lower bin boundaries
ENERG_HI - Energy upper bin boundaries
BKG      - Background template (or BGD as legacy column name)

The data are stored in the m_background member. The DETX and DETY axes will be set to radians, the energy axis will be set to log10. The data are expected to be given in unit of events per MeV, second and steradian, where the time is the real ontime.

This method ignores all column names that are not the mandatory column names in the FITS table.

Definition at line 298 of file GCTABackground3D.cpp.

References GCTAResponseTable::clear(), GFitsTable::clone(), m_background, GFitsTable::ncols(), GCTAResponseTable::read(), GFitsTable::remove(), and set_members().

Referenced by load().

void GCTABackground3D::save	(	const GFilename &	filename,
		const bool &	clobber = `false`
	)		const

Save background into FITS file.

Parameters

[in]	filename	Background table FITS file name.
[in]	clobber	Overwrite existing file? (default: false)

Saves background 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) background extension. The extension name can be specified as part of the filename, or if no extension name is given, is assumed to be BACKGROUND.

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

Definition at line 410 of file GCTABackground3D.cpp.

References GFitsHDU::extname(), GFilename::extname(), gammalib::extname_cta_background3d, GFits::remove(), table(), GFilename::url(), and write().

void GCTABackground3D::set_members ( void )

private

Set members from background table.

Exceptions

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

Set class members based on the background table. The DETX and DETY axes will be set to radians, the energy axis will be set to log10.

Definition at line 814 of file GCTABackground3D.cpp.

Referenced by read(), and table().

double GCTABackground3D::solid_angle	(	const double &	detx1,
		const double &	dety1,
		const double &	detx2,
		const double &	dety2,
		const double &	detx3,
		const double &	dety3
	)		const

private

Compute solid angle of pixel wedge.

Parameters

[in]	detx1	DETX of first edge.
[in]	dety1	DETY of first edge.
[in]	detx2	DETX of second edge.
[in]	dety2	DETY of second edge.
[in]	detx3	DETX of third edge.
[in]	dety3	DETY of third edge.

Returns: Solid angle (steradians).

Estimate the solid angle subtended by 3 coordinates using Huilier's theorem.

Below, the definiton of the pixel cornes and sides are shown as used within the code.

        a12
    1---------2
    |        / 
    |       /  
    |      /   
    |     /    
 a13|    /a23
    |   / 
    |  / 
    | /
    |/

Definition at line 1141 of file GCTABackground3D.cpp.

References atan(), gammalib::atan2(), GSkyDir::dist(), gammalib::pihalf, GSkyDir::radec(), sqrt(), and tan().

Referenced by init_mc_cache().

const GModelSpectralNodes & GCTABackground3D::spectrum ( void ) const

inlinevirtual

Get response cube spectrum.

Returns: Response cube spectrum.

Returns the response cube spectrum.

Implements GCTABackground.

Definition at line 166 of file GCTABackground3D.hpp.

References init_mc_cache(), m_mc_spectrum, and GModelSpectralNodes::nodes().

const GCTAResponseTable & GCTABackground3D::table ( void ) const

inline

Return response table.

Returns: Response table.

Definition at line 193 of file GCTABackground3D.hpp.

References m_background.

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

void GCTABackground3D::table ( const GCTAResponseTable & table )

inline

Assign response table.

Parameters

[in] table Response table.

Definition at line 205 of file GCTABackground3D.hpp.

References m_background, set_members(), and table().

void GCTABackground3D::write ( GFitsBinTable & table ) const

Write background into FITS table.

Parameters

[in] table FITS binary table.

Writes background into a FITS binary table.

Todo:: Add necessary keywords.

Definition at line 341 of file GCTABackground3D.cpp.

References m_background, and GCTAResponseTable::write().

Referenced by save().

Member Data Documentation

GCTAResponseTable GCTABackground3D::m_background

private

Background response table.

Definition at line 110 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_mc_max_rate(), init_members(), is_valid(), mc(), operator()(), print(), rate(), read(), set_members(), table(), and write().

double GCTABackground3D::m_detx_max

private

DETX maximum (radians)

Definition at line 121 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), mc(), operator()(), rate_ebin(), and set_members().

double GCTABackground3D::m_detx_min

private

DETX minimum (radians)

Definition at line 120 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), mc(), operator()(), rate_ebin(), and set_members().

double GCTABackground3D::m_dety_max

private

DETY maximum (radians)

Definition at line 123 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), mc(), operator()(), rate_ebin(), and set_members().

double GCTABackground3D::m_dety_min

private

DETY minimum (radians)

Definition at line 122 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), mc(), operator()(), rate_ebin(), and set_members().

GEnergies GCTABackground3D::m_energy

private

Vector of energies.

Definition at line 111 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), rate_ebin(), and set_members().

GFilename GCTABackground3D::m_filename

private

Name of background response file.

Definition at line 109 of file GCTABackground3D.hpp.

Referenced by copy_members(), filename(), init_members(), load(), and print().

int GCTABackground3D::m_inx_bgd

private

Background index.

Definition at line 115 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_max_rate(), init_members(), rate(), and set_members().

int GCTABackground3D::m_inx_detx

private

DETX index.

Definition at line 112 of file GCTABackground3D.hpp.

Referenced by copy_members(), index(), init_members(), print(), rate(), and set_members().

int GCTABackground3D::m_inx_dety

private

DETY index.

Definition at line 113 of file GCTABackground3D.hpp.

Referenced by copy_members(), index(), init_members(), print(), rate(), and set_members().

int GCTABackground3D::m_inx_energy

private

Energy index.

Definition at line 114 of file GCTABackground3D.hpp.

Referenced by copy_members(), index(), init_mc_cache(), init_members(), mc(), operator()(), print(), and set_members().

double GCTABackground3D::m_logE_max

private

Log10(E/TeV) maximum.

Definition at line 125 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_members(), and set_members().

double GCTABackground3D::m_logE_min

private

Log10(E/TeV) minimum.

Definition at line 124 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_members(), and set_members().

std::vector<double> GCTABackground3D::m_mc_max

mutableprivate

Maximum background rate.

Definition at line 128 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_mc_max_rate(), init_members(), and mc().

GModelSpectralNodes GCTABackground3D::m_mc_spectrum

mutableprivate

Response cube spectrum.

Definition at line 129 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_members(), mc(), and spectrum().

int GCTABackground3D::m_num[3]

private

Array of number of bins.

Definition at line 119 of file GCTABackground3D.hpp.

Referenced by copy_members(), index(), init_members(), and set_members().

int GCTABackground3D::m_num_detx

private

Number of DETX bins.

Definition at line 116 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_mc_max_rate(), init_members(), print(), and set_members().

int GCTABackground3D::m_num_dety

private

Number of DETY bins.

Definition at line 117 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_mc_max_rate(), init_members(), print(), and set_members().

int GCTABackground3D::m_num_energy

private

Number of energy bins.

Definition at line 118 of file GCTABackground3D.hpp.

Referenced by copy_members(), init_mc_cache(), init_mc_max_rate(), init_members(), print(), and set_members().

The documentation for this class was generated from the following files:

inst/cta/include/GCTABackground3D.hpp
inst/cta/src/GCTABackground3D.cpp

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