CTA cube background class. More...

#include <GCTACubeBackground.hpp>

Inheritance diagram for GCTACubeBackground:

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

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

	GCTACubeBackground (const GCTAEventCube &cube)
	Event cube constructor. More...

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

	GCTACubeBackground (const std::string &wcs, const std::string &coords, const double &x, const double &y, const double &dx, const double &dy, const int &nx, const int &ny, const GEbounds &ebounds)
	Background cube constructor. More...

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

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

double	operator() (const GCTAInstDir &dir, const GEnergy &energy) const
	Return background rate in units of events MeV \(^{-1}\) s \(^{-1}\) sr \(^{-1}\). More...

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

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

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

void	fill (const GObservations &obs, GLog *log=NULL)
	Fill background cube from observation container. More...

double	integral (const double &logE) const
	Return spatially integrated background rate in units of events MeV \(^{-1}\) s \(^{-1}\). More...

void	read (const GFits &fits)
	Read background cube from FITS object. More...

void	write (GFits &file) const
	Write CTA background cube into FITS object. More...

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

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

const GSkyMap &	cube (void) const
	Return background cube. More...

const GEbounds &	ebounds (void) const
	Return energy boundaries. More...

const GFilename &	filename (void) const
	Return background cube filename. More...

std::string	print (const GChatter &chatter=NORMAL) const
	Print background information. 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 GCTACubeBackground &bgd)
	Copy class members. More...

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

void	set_eng_axis (void)
	Set nodes for a logarithmic (base 10) energy axis. More...

void	update (const double &logE) const
	Update 1D cache. More...

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

GSkyMap	m_cube
	Background cube. More...

GEbounds	m_ebounds
	Energy boundaries of background cube. More...

GNodeArray	m_elogmeans
	Mean energy for the background cube. More...

int	m_inx_left
	Index of left node. More...

int	m_inx_right
	Index of right node. More...

double	m_wgt_left
	Weight of left node. More...

double	m_wgt_right
	Weight of right node. More...

Detailed Description

CTA cube background class.

Definition at line 50 of file GCTACubeBackground.hpp.

Constructor & Destructor Documentation

GCTACubeBackground::GCTACubeBackground ( void )

Void constructor.

Definition at line 72 of file GCTACubeBackground.cpp.

References init_members().

Referenced by clone().

GCTACubeBackground::GCTACubeBackground ( const GFilename & filename )

explicit

File constructor.

Parameters

[in] filename FITS file name.

Construct instance by loading the background information from a FITS file.

Definition at line 89 of file GCTACubeBackground.cpp.

References init_members(), and load().

GCTACubeBackground::GCTACubeBackground ( const GCTAEventCube & cube )

explicit

Event cube constructor.

Parameters

[in] cube Event cube.

Construct background cube using the same binning and sky projection that is used for the event cube.

Definition at line 110 of file GCTACubeBackground.cpp.

References GCTAEventCube::counts(), GEvents::ebounds(), init_members(), m_cube, m_ebounds, GSkyMap::nmaps(), set_eng_axis(), and GEbounds::size().

GCTACubeBackground::GCTACubeBackground ( const GCTACubeBackground & bgd )

Copy constructor.

Parameters

[in] bgd Background.

Definition at line 140 of file GCTACubeBackground.cpp.

References copy_members(), and init_members().

GCTACubeBackground::GCTACubeBackground	(	const std::string &	wcs,
		const std::string &	coords,
		const double &	x,
		const double &	y,
		const double &	dx,
		const double &	dy,
		const int &	nx,
		const int &	ny,
		const GEbounds &	ebounds
	)

Background cube constructor.

Parameters

[in]	wcs	World Coordinate System.
[in]	coords	Coordinate System (CEL or GAL).
[in]	x	X coordinate of sky map centre (deg).
[in]	y	Y coordinate of sky map centre (deg).
[in]	dx	Pixel size in x direction at centre (deg/pixel).
[in]	dy	Pixel size in y direction at centre (deg/pixel).
[in]	nx	Number of pixels in x direction.
[in]	ny	Number of pixels in y direction.
[in]	ebounds	Energy boundaries.

Constructs a background cube by specifying the sky map grid and the energies.

Definition at line 169 of file GCTACubeBackground.cpp.

References ebounds(), init_members(), m_cube, m_ebounds, set_eng_axis(), and GEbounds::size().

GCTACubeBackground::~GCTACubeBackground ( void )

virtual

Destructor.

Definition at line 199 of file GCTACubeBackground.cpp.

References free_members().

Member Function Documentation

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

inlinevirtual

Return class name.

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

Implements GBase.

Definition at line 119 of file GCTACubeBackground.hpp.

void GCTACubeBackground::clear ( void )

virtual

Clear background.

This method properly resets the background to an initial state.

Implements GBase.

Definition at line 306 of file GCTACubeBackground.cpp.

References free_members(), and init_members().

Referenced by GCTAResponseCube::init_members(), and read().

GCTACubeBackground * GCTACubeBackground::clone ( void ) const

virtual

Clone background.

Returns: Pointer to deep copy of background.

Implements GBase.

Definition at line 324 of file GCTACubeBackground.cpp.

References GCTACubeBackground().

void GCTACubeBackground::copy_members ( const GCTACubeBackground & bgd )

private

Copy class members.

Parameters

[in] bgd Background.

Definition at line 761 of file GCTACubeBackground.cpp.

References m_cube, m_ebounds, m_elogmeans, m_filename, m_inx_left, m_inx_right, m_wgt_left, and m_wgt_right.

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

const GSkyMap & GCTACubeBackground::cube ( void ) const

inline

Return background cube.

Returns: Sky map holding the background cube.

Returns the GSkyMap object that is used to store the background cube information.

Definition at line 134 of file GCTACubeBackground.hpp.

References m_cube.

const GEbounds & GCTACubeBackground::ebounds ( void ) const

inline

Return energy boundaries.

Returns: Energy boundaries

Definition at line 146 of file GCTACubeBackground.hpp.

References m_ebounds.

Referenced by GCTACubeBackground().

const GFilename & GCTACubeBackground::filename ( void ) const

inline

Return background cube filename.

Returns: Background cube filename.

Returns the filename from which the background cube was loaded or into which the background cube has been saved.

Definition at line 161 of file GCTACubeBackground.hpp.

References m_filename.

Referenced by load(), save(), and GCTAResponseCube::write().

void GCTACubeBackground::fill	(	const GObservations &	obs,
		GLog *	log = `NULL`
	)

Fill background cube from observation container.

Parameters

[in]	obs	Observation container.
[in]	log	Pointer to logger (optional).

Exceptions

GException::invalid_value No event list found in CTA observations.

Set the background cube by computing the ontime weighted background rate for all CTA observations in an observation container. The cube pixel values are computed as the sum over the background rates.

Definition at line 343 of file GCTACubeBackground.cpp.

References GCTARoi::centre(), GCTARoi::contains(), GEbounds::contains(), GCTAEventBin::counts(), GCTAEventCube::counts(), GCTAEventBin::dir(), GCTAInstDir::dir(), GCTAObservation::ebounds(), GEbounds::elogmean(), GEbounds::emax(), GEbounds::emin(), GCTAEventBin::energy(), GCTAObservation::eventtype(), G_FILL, GEvents::gti(), GCTAObservation::gti(), GObservation::id(), GCTAObservation::instrument(), GCTARoi::is_valid(), m_cube, m_ebounds, GObservations::models(), GObservation::name(), GCTAEventCube::npix(), GCTAObservation::ontime(), GSkyMap::overlaps(), GCTAObservation::pointing(), GCTARoi::radius(), GCTAObservation::roi(), GCTAEventCube::size(), GEbounds::size(), and GObservations::size().

void GCTACubeBackground::free_members ( void )

private

Delete class members.

Definition at line 783 of file GCTACubeBackground.cpp.

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

void GCTACubeBackground::init_members ( void )

private

Initialise class members.

Definition at line 737 of file GCTACubeBackground.cpp.

References GNodeArray::clear(), GFilename::clear(), GEbounds::clear(), GSkyMap::clear(), m_cube, m_ebounds, m_elogmeans, m_filename, m_inx_left, m_inx_right, m_wgt_left, and m_wgt_right.

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

double GCTACubeBackground::integral ( const double & logE ) const

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

Parameters

[in] logE Logarithm (base 10) of energy in TeV

Returns: Spatially integrated background rate (events MeV \(^{-1}\) s \(^{-1}\))

Spatially integrates the background cube at a given energy. This method performs an interpolation between the energy maps. The integration is performed by summing over all bin contents multiplied by the solid angle of the bin.

Definition at line 539 of file GCTACubeBackground.cpp.

References m_cube, m_inx_left, m_inx_right, m_wgt_left, m_wgt_right, GSkyMap::npix(), and update().

Referenced by GCTAModelCubeBackground::npred().

void GCTACubeBackground::load ( const GFilename & filename )

Load background cube from FITS file.

Parameters

[in] filename FITS file.

Loads the background cube from a FITS file.

Definition at line 626 of file GCTACubeBackground.cpp.

References GFits::close(), filename(), m_filename, and read().

Referenced by GCTACubeBackground(), and GCTAResponseCube::read().

double GCTACubeBackground::operator()	(	const GCTAInstDir &	dir,
		const GEnergy &	energy
	)		const

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

Parameters

[in]	dir	Reconstructed event position where rate should be computed
[in]	energy	Energy at which the rate should be computed

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

Returns the background rate for a giben instrument direction and energy. The rate is given per ontime. The method assures that the background rate never becomes negative.

The method interpolates logarithmically in the energy direction.

Definition at line 256 of file GCTACubeBackground.cpp.

References abs(), GCTAInstDir::dir(), exp(), log(), GEnergy::log10TeV(), m_cube, m_inx_left, m_inx_right, m_wgt_left, m_wgt_right, and update().

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

Assignment operator.

Parameters

[in] bgd Background cube.

Returns: Background cube.

Definition at line 221 of file GCTACubeBackground.cpp.

References copy_members(), free_members(), and init_members().

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

virtual

Print background information.

Parameters

[in] chatter Chattiness.

Returns: String containing background information.

Implements GBase.

Definition at line 695 of file GCTACubeBackground.cpp.

References m_cube, m_ebounds, m_filename, gammalib::parformat(), GEbounds::print(), GSkyMap::print(), SILENT, and GEbounds::size().

Referenced by GCTAResponseCube::print().

void GCTACubeBackground::read ( const GFits & fits )

Read background cube from FITS object.

Parameters

[in] fits FITS object.

Read the background cube from a FITS object.

Definition at line 571 of file GCTACubeBackground.cpp.

References clear(), gammalib::extname_ebounds, GFits::image(), m_cube, m_ebounds, GEbounds::read(), GSkyMap::read(), set_eng_axis(), and GFits::table().

Referenced by load().

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

Save background cube into FITS file.

Parameters

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

Save the background cube into a FITS file.

Definition at line 660 of file GCTACubeBackground.cpp.

References GFits::close(), filename(), m_filename, GFits::saveto(), and write().

void GCTACubeBackground::set_eng_axis ( void )

private

Set nodes for a logarithmic (base 10) energy axis.

Set axis nodes so that each node is the logarithm of the energy values.

Definition at line 796 of file GCTACubeBackground.cpp.

References GNodeArray::append(), GNodeArray::clear(), GEbounds::elogmean(), GEnergy::log10TeV(), m_ebounds, m_elogmeans, and GEbounds::size().

Referenced by GCTACubeBackground(), and read().

void GCTACubeBackground::update ( const double & logE ) const

private

Update 1D cache.

Parameters

[in] logE Log10 energy in TeV.

Updates the 1D interpolation cache. The interpolation cache is composed of two indices and weights that define 2 data values of the 2D skymap that are used for linear interpolation.