CTA 2D energy dispersion class. More...

#include <GCTAEdisp2D.hpp>

Inheritance diagram for GCTAEdisp2D:

Classes
class	edisp_ereco_kern

Public Member Functions
	GCTAEdisp2D (void)
	Void constructor. More...

	GCTAEdisp2D (const GFilename &filename)
	File constructor. More...

	GCTAEdisp2D (const GCTAEdisp2D &edisp)
	Copy constructor. More...

virtual	~GCTAEdisp2D (void)
	Destructor. More...

GCTAEdisp2D &	operator= (const GCTAEdisp2D &edisp)
	Assignment operator. More...

double	operator() (const GEnergy &ereco, const GEnergy &etrue, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Return energy dispersion in units of MeV \(^{-1}\). More...

void	clear (void)
	Clear energy dispersion. More...

GCTAEdisp2D *	clone (void) const
	Clone energy dispersion. More...

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

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

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

GEnergy	mc (GRan &ran, const GEnergy &etrue, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Simulate energy dispersion. More...

GEbounds	ereco_bounds (const GEnergy &etrue, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Return observed energy interval that contains the energy dispersion. More...

GEbounds	etrue_bounds (const GEnergy &ereco, const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Return true energy interval that contains the energy dispersion. More...

double	prob_erecobin (const GEnergy &ereco_min, const GEnergy &ereco_max, const GEnergy &etrue, const double &theta) const
	Return energy dispersion probability for reconstructed energy interval. More...

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

void	fetch (void) const
	Fetch energy dispersion. 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 energy dispersion from FITS table. More...

void	write (GFitsBinTable &table) const
	Write energy dispersion into FITS binary table. More...

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

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

	GCTAEdisp (const GCTAEdisp &edisp)
	Copy constructor. More...

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

GCTAEdisp &	operator= (const GCTAEdisp &edisp)
	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 GCTAEdisp2D &edisp)
	Copy class members. More...

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

GEnergy	etrue (const int &ietrue) const
	Get true energy. More...

double	migra (const int &imigra) const
	Get migration. More...

double	theta (const int &itheta) const
	Get offset angle in radiaus. More...

void	compute_ereco_bounds (const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Compute vector of reconstructed energy bounds. More...

void	compute_etrue_bounds (const double &theta=0.0, const double &phi=0.0, const double &zenith=0.0, const double &azimuth=0.0) const
	Compute vector of true energy boundaries. More...

void	set_table (void)
	Set table. More...

void	set_boundaries (void)
	Set energy dispersion boundaries. More...

void	set_max_edisp (void)
	Set array of maximum energy dispersion values. More...

double	get_max_edisp (const GEnergy &etrue, const double &theta) const
	Get maximum energy dispersion value. More...

void	normalize_table (void)
	Normalize energy dispersion table. More...

int	table_index (const int &ietrue, const int &imigra, const int &itheta) const
	Return index of response table element. More...

int	table_stride (const int &axis) const
	Return stride of response table axis. More...

double	table_value (const int &base_ll, const int &base_lr, const int &base_rl, const int &base_rr, const double &wgt_el, const double &wgt_er, const double &wgt_tl, const double &wgt_tr, const int &offset) const
	Return bi-linearly interpolate table value for given migration bin. More...

double	table_value (const int &base_ll, const int &base_lr, const int &base_rl, const int &base_rr, const double &wgt_el, const double &wgt_er, const double &wgt_tl, const double &wgt_tr, const double &migra) const
	Return bi-linearly interpolate table value for given migration value. More...

void	smooth_table (void)
	Smoothed energy dispersion table. More...

GNdarray	smooth_array (const GNdarray &array, const int &nstart, const int &nstop, const double &limit) const
	Smoothed array. More...

double	smoothed_array_value (const int &inx, const GNdarray &array, const int &nodes, const double &limit) const
	Get smoothed array value. More...

void	get_moments (const int &itheta, GNdarray mean, GNdarray rms, GNdarray *total) const
	Compute moments. More...

void	get_mean_rms (const GNdarray &array, double mean, double rms) const
	Compute mean and root mean square of migration array. More...

GNdarray	gaussian_array (const double &mean, const double &rms, const double &total) const
	Return Gaussian approximation of energy dispersion array. More...

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

GCTAResponseTable	m_edisp
	Edisp response table. More...

bool	m_fetched
	Signals that Edisp has been fetched. More...

int	m_inx_etrue
	True energy index. More...

int	m_inx_migra
	Migration index. More...

int	m_inx_theta
	Theta index. More...

int	m_inx_matrix
	Matrix. More...

double	m_logEsrc_min
	Minimum logE (log10(E/TeV)) More...

double	m_logEsrc_max
	Maximum logE (log10(E/TeV)) More...

double	m_migra_min
	Minimum migration. More...

double	m_migra_max
	Maximum migration. More...

double	m_theta_min
	Minimum theta (radians) More...

double	m_theta_max
	Maximum theta (radians) More...

std::vector< double >	m_max_edisp
	Maximum Edisp. More...

bool	m_ereco_bounds_computed

bool	m_etrue_bounds_computed

double	m_last_theta_ereco

double	m_last_theta_etrue

GEnergy	m_last_etrue

GEnergy	m_last_ereco

int	m_index_ereco

int	m_index_etrue

std::vector< GEbounds >	m_ereco_bounds

std::vector< GEbounds >	m_etrue_bounds

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

void	copy_members (const GCTAEdisp &edisp)
	Copy class members. More...

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

Detailed Description

CTA 2D energy dispersion class.

This class implements the energy dispersion for the CTA 2D response. The CTA 2D energy dispersion is in fact a 3-dimensional function, where the energy dispersion

\[ E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) \]

is given as function of true energy \(E_{\rm true}\), reconstructed energy \(E_{\rm reco}\) and offset angle \(\theta\). The GCTAEdisp2D::operator() returns the value of the function \(E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta)\) in units of MeV \(^{-1}\) with

\[ \int_{E_{\rm reco}^{\rm min}}^{E_{\rm reco}^{\rm max}} E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) \, dE_{\rm reco} = 1 \]

The energy dispersion is stored internally as a 3-dimensional response table, spanned by true energy \(E_{\rm true}\), migration \(m=E_{\rm reco}/E_{\rm true}\) and offset angle \(\theta\), with

\[ E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) = \frac{E_{\rm disp}(m | E_{\rm true}, \theta)}{E_{\rm true}} \]

and

\[ \int_{m_{\rm min}}^{m_{\rm max}} E_{\rm disp}(m | E_{\rm true}, \theta) \, dm = 1 \]

Definition at line 90 of file GCTAEdisp2D.hpp.

Constructor & Destructor Documentation

GCTAEdisp2D::GCTAEdisp2D ( void )

Void constructor.

Constructs empty energy dispersion.

Definition at line 76 of file GCTAEdisp2D.cpp.

References init_members().

Referenced by clone().

GCTAEdisp2D::GCTAEdisp2D ( const GFilename & filename )

explicit

File constructor.

Parameters

[in] filename FITS file name.

Constructs energy dispersion from a FITS file.

Definition at line 93 of file GCTAEdisp2D.cpp.

References init_members(), and load().

GCTAEdisp2D::GCTAEdisp2D ( const GCTAEdisp2D & edisp )

Copy constructor.

Parameters

[in] edisp Energy dispersion.

Constructs energy dispersion by copying from another energy dispersion.

Definition at line 114 of file GCTAEdisp2D.cpp.

References copy_members(), and init_members().

GCTAEdisp2D::~GCTAEdisp2D ( void )

virtual

Destructor.

Destructs energy dispersion.

Definition at line 132 of file GCTAEdisp2D.cpp.

References free_members().

Member Function Documentation

std::string GCTAEdisp2D::classname ( void ) const

inlinevirtual

Return class name.

Returns: String containing the class name ("GCTAEdisp2D").

Implements GCTAEdisp.

Definition at line 260 of file GCTAEdisp2D.hpp.

void GCTAEdisp2D::clear ( void )

virtual

Clear energy dispersion.

Clears energy dispersion.

Implements GCTAEdisp.

Definition at line 270 of file GCTAEdisp2D.cpp.

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

Referenced by load().

GCTAEdisp2D * GCTAEdisp2D::clone ( void ) const

virtual

Clone energy dispersion.

Returns: Deep copy of energy dispersion.

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

Implements GCTAEdisp.

Definition at line 292 of file GCTAEdisp2D.cpp.

References GCTAEdisp2D().

void GCTAEdisp2D::compute_ereco_bounds	(	const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

private

Compute vector of reconstructed energy bounds.

Parameters

[in]	theta	Offset angle (radians).
[in]	phi	Azimuth angle (radians).
[in]	zenith	Zenith angle (radians).
[in]	azimuth	Azimuth angle (radians).

Computes for all true energies the energy boundaries of the reconstructed energies covered by valid migration matrix elements. Only matrix elements with values >= 1.0e-12 are considered as valid elements. In case that no matrix elements are found of a given true energy, the interval of observed energies will be set to 0,0.

Definition at line 1186 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), etrue(), GEnergy::log10TeV(), m_edisp, m_ereco_bounds, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, migra(), GEnergy::TeV(), and theta().

Referenced by ereco_bounds().

void GCTAEdisp2D::compute_etrue_bounds	(	const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

private

Compute vector of true energy boundaries.

Parameters

[in]	theta	Offset angle (radians).
[in]	phi	Azimuth angle (radians).
[in]	zenith	Zenith angle (radians).
[in]	azimuth	Azimuth angle (radians).

Computes for all observed energies the energy boundaries of the true energies covered by valid migration matrix elements. Only matrix elements with values >= 1.0e-12 are considered as valid elements. In case that no matrix elements are found of a given observed energy, the interval of true energies will be set to 0,0.

Definition at line 1294 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), GEnergy::clear(), etrue(), m_edisp, m_etrue_bounds, m_inx_etrue, m_inx_migra, migra(), and operator()().

Referenced by etrue_bounds().

void GCTAEdisp2D::copy_members ( const GCTAEdisp2D & edisp )

private

Copy class members.

Parameters

[in] edisp Energy dispersion.

Definition at line 1071 of file GCTAEdisp2D.cpp.

References m_edisp, m_ereco_bounds, m_ereco_bounds_computed, m_etrue_bounds, m_etrue_bounds_computed, m_fetched, m_filename, m_index_ereco, m_index_etrue, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, m_last_ereco, m_last_etrue, m_last_theta_ereco, m_last_theta_etrue, m_logEsrc_max, m_logEsrc_min, m_max_edisp, m_migra_max, m_migra_min, m_theta_max, and m_theta_min.

Referenced by GCTAEdisp2D(), and operator=().

GEbounds GCTAEdisp2D::ereco_bounds	(	const GEnergy &	etrue,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

virtual

Return observed energy interval that contains the energy dispersion.

Parameters

[in]	etrue	True photon energy.
[in]	theta	Offset angle in camera system (radians).
[in]	phi	Azimuth angle in camera system (radians). Not used.
[in]	zenith	Zenith angle in Earth system (radians). Not used.
[in]	azimuth	Azimuth angle in Earth system (radians). Not used.

Returns: Observed energy boundaries.

Returns the band of observed energies outside of which the energy dispersion becomes negligible for a given true energy etrue and offset angle theta.

Implements GCTAEdisp.

Definition at line 588 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_lo(), compute_ereco_bounds(), etrue(), fetch(), m_edisp, m_ereco_bounds, m_ereco_bounds_computed, m_index_ereco, m_inx_etrue, m_last_etrue, m_last_theta_ereco, GEnergy::TeV(), and theta().

Referenced by mc(), and normalize_table().

GEnergy GCTAEdisp2D::etrue ( const int & ietrue ) const

private

Get true energy.

Parameters

[in] ietrue True energy index.

Returns: True energy.

Definition at line 1122 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), m_edisp, m_inx_etrue, sqrt(), and GEnergy::TeV().

Referenced by compute_ereco_bounds(), compute_etrue_bounds(), ereco_bounds(), mc(), normalize_table(), prob_erecobin(), and set_max_edisp().

GEbounds GCTAEdisp2D::etrue_bounds	(	const GEnergy &	ereco,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

virtual

Return true energy interval that contains the energy dispersion.

Parameters

[in]	ereco	Reconstructed event energy.
[in]	theta	Offset angle in camera system (radians).
[in]	phi	Azimuth angle in camera system (radians). Not used.
[in]	zenith	Zenith angle in Earth system (radians). Not used.
[in]	azimuth	Azimuth angle in Earth system (radians). Not used.

Returns: True energy boundaries.

Returns the band of true photon energies outside of which the energy dispersion becomes negligible for a given observed energy ereco and offset angle theta.

Implements GCTAEdisp.

Definition at line 657 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_lo(), compute_etrue_bounds(), fetch(), m_edisp, m_etrue_bounds, m_etrue_bounds_computed, m_index_etrue, m_inx_etrue, m_last_ereco, m_last_theta_etrue, GEnergy::TeV(), and theta().

void GCTAEdisp2D::fetch ( void ) const

Fetch energy dispersion.

Exceptions

GException::file_error File not found. Unable to load energy dispersion.

Fetches the energy dispersion by reading it from a FITS file.

If the filename contains no extension name the method scans the HDUCLASS keywords of all extensions and loads the energy dispersion from the first extension for which HDUCLAS4=EDISP_2D.

Otherwise, the background will be loaded from the ENERGY DISPERSION extension.

This method does nothing if the energy dispersion is already loaded, if there is nothing to fetch, or if the m_filename member is empty.

The method is thread save. The method checks whether the file from which the energy dispersion should be loaded actually exists.

Definition at line 734 of file GCTAEdisp2D.cpp.

References GFits::close(), GFilename::exists(), GFilename::extname(), gammalib::extname_cta_edisp2d, G_FETCH, gammalib::gadf_hduclas4(), GFilename::is_empty(), m_fetched, m_filename, read(), GFits::table(), and table().

Referenced by ereco_bounds(), etrue_bounds(), mc(), operator()(), print(), prob_erecobin(), table(), and write().

GFilename GCTAEdisp2D::filename ( void ) const

inlinevirtual

Return filename.

Returns: Name of FITS file from which energy dispersion was loaded.

Implements GCTAEdisp.

Definition at line 272 of file GCTAEdisp2D.hpp.

References m_filename.

Referenced by load().

void GCTAEdisp2D::free_members ( void )

private

Delete class members.

Definition at line 1109 of file GCTAEdisp2D.cpp.

Referenced by clear(), operator=(), and ~GCTAEdisp2D().

GNdarray GCTAEdisp2D::gaussian_array	(	const double &	mean,
		const double &	rms,
		const double &	total
	)		const

private

Return Gaussian approximation of energy dispersion array.

Parameters

[in]	mean	Gaussian mean.
[in]	rms	Gaussian rms.
[in]	total	Gaussian total.

Returns: Gaussian approximation of energy dispersion array.

Returns a Gaussian approximation of the energy dispersion array by computing the mean migration value and its root mean square and by using these values as the centre and the width of a Gaussian function. The Gaussian function is normalized so that the sum of the output array is unity.

Definition at line 2196 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), GCTAResponseTable::axis_nodes(), exp(), m_edisp, m_inx_migra, and GNodeArray::size().

Referenced by smooth_table().

double GCTAEdisp2D::get_max_edisp	(	const GEnergy &	etrue,
		const double &	theta
	)		const

private

Get maximum energy dispersion value.

Parameters

[in]	etrue	True photon energy.
[in]	theta	Offset angle (radians).

Returns: Maximum energy dispersion value.

For a given true energy etrue and offset angle theta, returns the maximum energy dispersion value that may occur. This method makes use of the internal array pre-computed by set_max_edisp().

If set_max_edisp() was not called, the method returns 0.

Definition at line 1556 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), GCTAResponseTable::axis_nodes(), GNodeArray::inx_left(), GNodeArray::inx_right(), GEnergy::log10TeV(), m_edisp, m_inx_etrue, m_inx_theta, m_max_edisp, and GNodeArray::set_value().

Referenced by mc().

void GCTAEdisp2D::get_mean_rms	(	const GNdarray &	array,
		double *	mean,
		double *	rms
	)		const

private

Compute mean and root mean square of migration array.

Parameters

[in]	array	Energy dispersion array.
[out]	mean	Pointer to mean migration value.
[out]	rms	Pointer to root mean square value.

Computes the mean and the root mean square of the migration array. If the migration array is empty the mean and root mean square values are set to zero.

The method does not check whether the mean and rms pointers are valid.

Definition at line 2147 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_nodes(), m_edisp, m_inx_migra, migra(), GNodeArray::size(), sqrt(), and sum().

Referenced by get_moments().

void GCTAEdisp2D::get_moments	(	const int &	itheta,
		GNdarray *	mean,
		GNdarray *	rms,
		GNdarray *	total
	)		const

private

Compute moments.

Parameters

[in]	itheta	Offset angle index.
[out]	mean	Pointer to mean array.
[out]	rms	Pointer to rms array.
[out]	total	Pointer to total array.

Computes the mean and root mean square values as function of true energy for a given offset angle.

Definition at line 2092 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), get_mean_rms(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, and sum().

Referenced by smooth_table().

void GCTAEdisp2D::init_members ( void )

private

Initialise class members.

Definition at line 1031 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::clear(), GFilename::clear(), m_edisp, m_ereco_bounds, m_ereco_bounds_computed, m_etrue_bounds, m_etrue_bounds_computed, m_fetched, m_filename, m_index_ereco, m_index_etrue, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, m_last_ereco, m_last_etrue, m_last_theta_ereco, m_last_theta_etrue, m_logEsrc_max, m_logEsrc_min, m_max_edisp, m_migra_max, m_migra_min, m_theta_max, m_theta_min, and GEnergy::TeV().

Referenced by clear(), GCTAEdisp2D(), and operator=().

void GCTAEdisp2D::load ( const GFilename & filename )

virtual

Load energy dispersion from FITS file.

Parameters

[in] filename FITS file name.

Loads the energy dispersion from a FITS file.

The method does not actually load the FITS file, which will only be loaded on request. Only the filename is stored. See the fetch() method for the actually loading of the energy dispersion.

Implements GCTAEdisp.

Definition at line 401 of file GCTAEdisp2D.cpp.

References clear(), filename(), and m_filename.

Referenced by GCTAEdisp2D().

GEnergy GCTAEdisp2D::mc	(	GRan &	ran,
		const GEnergy &	etrue,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

virtual

Simulate energy dispersion.

Parameters

[in]	ran	Random number generator.
[in]	etrue	True photon energy.
[in]	theta	Offset angle in camera system (radians).
[in]	phi	Azimuth angle in camera system (radians). Not used.
[in]	zenith	Zenith angle in Earth system (radians). Not used.
[in]	azimuth	Azimuth angle in Earth system (radians). Not used.

Returns: Reconstructed energy.

Exceptions

GException::invalid_return_value No energy dispersion information found for parameters or energy dispersion matrix is empty.

Draws reconstructed energy value given a true energy etrue and offset angle theta. If no energy dispersion information is available the method will return the true photon energy.

Implements GCTAEdisp.

Definition at line 483 of file GCTAEdisp2D.cpp.

References GEbounds::emax(), GEbounds::emin(), ereco_bounds(), etrue(), fetch(), G_MC, get_max_edisp(), operator()(), GEnergy::print(), gammalib::rad2deg, gammalib::str(), GEnergy::TeV(), and GRan::uniform().

double GCTAEdisp2D::migra ( const int & imigra ) const

private

Get migration.

Parameters

[in] imigra Migration index.

Returns: Migration.

Definition at line 1143 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), m_edisp, and m_inx_migra.

Referenced by compute_ereco_bounds(), compute_etrue_bounds(), get_mean_rms(), and operator()().

void GCTAEdisp2D::normalize_table ( void )

private

Normalize energy dispersion table.

Normalize the energy dispersion table using

\[ \int_{E_{\rm reco}^{\rm min}}^{E_{\rm reco}^{\rm max}} E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) \, dE_{\rm reco} = 1 \]

where \(E_{\rm reco}_{\rm min}\) and \(E_{\rm reco}_{\rm max}\) is the minimum and maximum migration value for a given true energy as returned by the ebounds_obs() method, and \(E_{\rm disp}(E_{\rm true}, E_{\rm reco}, \theta)\) is the energy dispersion returned by the operator(), given in units of \(MeV^{-1}\).

The normalisation is performed for each \(E_{\rm true}\) and \(\theta\) bin using a Romberg integration method. Since the normalisation may affect the energy boundaries \(E_{\rm reco}^{\rm min}\) and \(E_{\rm reco}^{\rm max}\), two normalisation passes are performed to stabilize the result.

Definition at line 1629 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), GEbounds::emax(), GEbounds::emin(), GIntegral::eps(), ereco_bounds(), etrue(), GEnergy::log10MeV(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, GIntegral::romberg(), GEbounds::size(), sum(), table_index(), table_stride(), and theta().

Referenced by set_table().

double GCTAEdisp2D::operator()	(	const GEnergy &	ereco,
		const GEnergy &	etrue,
		const double &	theta = `0.0`,
		const double &	phi = `0.0`,
		const double &	zenith = `0.0`,
		const double &	azimuth = `0.0`
	)		const

virtual

Return energy dispersion in units of MeV \(^{-1}\).

Parameters

[in]	ereco	Reconstructed photon energy.
[in]	etrue	True photon energy.
[in]	theta	Offset angle in camera system (radians).
[in]	phi	Azimuth angle in camera system (radians). Not used.
[in]	zenith	Zenith angle in Earth system (radians). Not used.
[in]	azimuth	Azimuth angle in Earth system (radians). Not used.

Returns: Energy dispersion (MeV \(^{-1}\))

Returns the energy dispersion

\[ E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) = \frac{E_{\rm disp}(m | E_{\rm true}, \theta)}{E_{\rm true}} \]

in units of MeV \(^{-1}\) where \(E_{\rm reco}\) is the reconstructed energy, \(E_{\rm true}\) is the true energy, and \(\theta\) is the offset angle.

Implements GCTAEdisp.

Definition at line 203 of file GCTAEdisp2D.cpp.

References fetch(), GEnergy::log10TeV(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, m_logEsrc_max, m_logEsrc_min, m_migra_max, m_migra_min, m_theta_max, m_theta_min, GEnergy::MeV(), migra(), and theta().

Referenced by compute_etrue_bounds(), and mc().

GCTAEdisp2D & GCTAEdisp2D::operator= ( const GCTAEdisp2D & edisp )

Assignment operator.

Parameters

[in] edisp Energy dispersion.

Returns: Energy dispersion.

Assigns energy dispersion.

Definition at line 156 of file GCTAEdisp2D.cpp.

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

std::string GCTAEdisp2D::print ( const GChatter & chatter = NORMAL ) const

virtual

Print energy dispersion information.

Parameters

[in] chatter Chattiness.

Returns: String containing energy dispersion information.

Implements GCTAEdisp.

Definition at line 962 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axes(), GCTAResponseTable::axis_bins(), GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), fetch(), m_edisp, m_filename, m_inx_etrue, m_inx_migra, m_inx_theta, gammalib::parformat(), SILENT, and gammalib::str().

double GCTAEdisp2D::prob_erecobin	(	const GEnergy &	ereco_min,
		const GEnergy &	ereco_max,
		const GEnergy &	etrue,
		const double &	theta
	)		const

virtual

Return energy dispersion probability for reconstructed energy interval.

Parameters

[in]	ereco_min	Minimum of reconstructed energy interval.
[in]	ereco_max	Maximum of reconstructed energy interval.
[in]	etrue	True energy.
[in]	theta	Offset angle (radians).

Returns: Integrated energy dispersion probability.

Computes

\[ \int_{E_{\rm reco}^{\rm min}}^{E_{\rm reco}^{\rm max}} E_{\rm disp}(E_{\rm reco} | E_{\rm true}, \theta) \, dE_{\rm reco} \]

where \(E_{\rm reco}\) is the reconstructed energy, \(E_{\rm true}\) is the true energy and \(\theta\) is the offset angle.

The method takes into account that the energy dispersion data are stored in a matrix and uses the trapezoidal rule for integration of the tabulated data. This assures the fastest possible integration.

Implements GCTAEdisp.

Definition at line 834 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_nodes(), etrue(), fetch(), GNodeArray::inx_left(), GNodeArray::inx_right(), GEnergy::log10TeV(), m_edisp, m_inx_etrue, m_inx_migra, m_inx_theta, m_logEsrc_max, m_logEsrc_min, m_migra_max, m_migra_min, m_theta_max, m_theta_min, GNodeArray::set_value(), GNodeArray::size(), table_index(), table_stride(), table_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

void GCTAEdisp2D::read ( const GFitsTable & table )

Read energy dispersion from FITS table.

Parameters

[in] table FITS table.

Exceptions

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

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

ENERG_LO - True energy lower bin boundaries (alternative name: ETRUE_LO)
ENERG_HI - True energy upper bin boundaries (alternative name: ETRUE_HI)
MIGRA_LO - Migration lower bin boundaries
MIGRA_HI - Migration upper bin boundaries
THETA_LO - Offset angle lower bin boundaries
THETA_HI - Offset angle upper bin boundaries
MATRIX   - Migration matrix

The data are stored in the m_edisp member. The energy axis will be set to \(log_{10} E_{\rm true}\), the offset angle axis to radians.

The method assures that the energy dispersion is properly normalised.

Definition at line 342 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axes(), GCTAResponseTable::clear(), G_READ, m_edisp, GCTAResponseTable::read(), set_table(), and gammalib::str().

Referenced by fetch().

void GCTAEdisp2D::save	(	const GFilename &	filename,
		const bool &	clobber = `false`
	)		const

Save energy dispersion table into FITS file.

Parameters

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

Saves energy dispersion 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) energy dispersion extension. The extension name can be specified as part of the filename, or if no extension name is given, is assumed to be ENERGY DISPERSION.

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

Definition at line 430 of file GCTAEdisp2D.cpp.

References GFitsHDU::extname(), GFilename::extname(), gammalib::extname_cta_edisp2d, GFits::remove(), table(), GFilename::url(), and write().

Referenced by set_table().

void GCTAEdisp2D::set_boundaries ( void )

private

Set energy dispersion boundaries.

Sets the data members m_logEsrc_min, m_logEsrc_max, m_migra_min, m_migra_max, m_theta_min and m_theta_max that define the validity range of the energy dispersion.

Definition at line 1468 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), GCTAResponseTable::axis_hi(), GCTAResponseTable::axis_lo(), gammalib::deg2rad, log10(), m_edisp, m_inx_etrue, m_inx_migra, m_inx_theta, m_logEsrc_max, m_logEsrc_min, m_migra_max, m_migra_min, m_theta_max, and m_theta_min.

Referenced by set_table().

void GCTAEdisp2D::set_max_edisp ( void )

private

Set array of maximum energy dispersion values.

Sets an internal array of maximum energy dispersion values for each given true photon energy and offset angle in the response table. This array will be used for Monte Carlo simulations.

Definition at line 1499 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), etrue(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, m_max_edisp, GEnergy::MeV(), table_index(), and table_stride().

Referenced by set_table().

void GCTAEdisp2D::set_table ( void )

private

Set table.

After assigning or loading a response table, performs all necessary steps to set the table.

For CTA, the method applies a kludge that smoothes the energy dispersion table to get rid of numerical fluctuations.

Sets the data members m_inx_etrue m_inx_migra m_inx_theta m_inx_matrix m_logEsrc_min m_logEsrc_max m_migra_min m_migra_max m_theta_min m_theta_max m_max_edisp

Definition at line 1416 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis(), GCTAResponseTable::axis_log10(), GCTAResponseTable::axis_radians(), GCTAResponseTable::has_axis(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, normalize_table(), save(), set_boundaries(), set_max_edisp(), smooth_table(), gammalib::strip_whitespace(), GCTAResponseTable::table(), and GCTAResponseTable::telescope().

Referenced by read(), and table().

GNdarray GCTAEdisp2D::smooth_array	(	const GNdarray &	array,
		const int &	nstart,
		const int &	nstop,
		const double &	limit
	)		const

private

Smoothed array.

Parameters

[in]	array	Array.
[in]	nstart	Number of nodes used for regression at first array value.
[in]	nstop	Number of nodes used for regression at last array value.
[in]	limit	Limit for array element exclusion.

Returns: Smoothed array.

Returns a smoothed array that is computed by locally adjusting a linear regression law to the array elements.

Definition at line 1949 of file GCTAEdisp2D.cpp.

References GNdarray::size(), and smoothed_array_value().

Referenced by smooth_table().

void GCTAEdisp2D::smooth_table ( void )

private

Smoothed energy dispersion table.

This method implements the kludge for CTA that reduces the statistical noise in the energy dispersion matrix.

Definition at line 1867 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), gaussian_array(), get_moments(), m_edisp, m_inx_etrue, m_inx_matrix, m_inx_migra, m_inx_theta, and smooth_array().

Referenced by set_table().

double GCTAEdisp2D::smoothed_array_value	(	const int &	inx,
		const GNdarray &	array,
		const int &	nodes,
		const double &	limit
	)		const

private

Get smoothed array value.

Parameters

[in]	inx	Index of array element.
[in]	array	Array.
[in]	nodes	Number of nodes used for regression.
[in]	limit	Limit for array element exclusion.

Returns: Smoothed array value.

Returns a smoothed array value that is derived from adjusting a linear law using regression to nodes adjacent array elements. Array elements with values below limit are excluded from the regression.

Definition at line 1984 of file GCTAEdisp2D.cpp.

References GNdarray::size().

Referenced by smooth_array().

const GCTAResponseTable & GCTAEdisp2D::table ( void ) const

inline

Return response table.

Returns: Reference to response table.

Definition at line 285 of file GCTAEdisp2D.hpp.

References fetch(), and m_edisp.

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

void GCTAEdisp2D::table ( const GCTAResponseTable & table )

Assign response table.

Parameters

[in] table Response table.

Assigns the response table for an energy dispersion.

Definition at line 305 of file GCTAEdisp2D.cpp.

References m_edisp, set_table(), and table().

int GCTAEdisp2D::table_index	(	const int &	ietrue,
		const int &	imigra,
		const int &	itheta
	)		const

private

Return index of response table element.

Parameters

[in]	ietrue	True energy index.
[in]	imigra	Migration index.
[in]	itheta	Offset index.

Returns: Index of response table element.

Definition at line 1720 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), m_edisp, m_inx_etrue, m_inx_migra, and m_inx_theta.

Referenced by normalize_table(), prob_erecobin(), and set_max_edisp().

int GCTAEdisp2D::table_stride ( const int & axis ) const

private

Return stride of response table axis.

Parameters

[in] axis Response table axis.

Returns: Stride of response table axis.

Definition at line 1745 of file GCTAEdisp2D.cpp.

References GCTAResponseTable::axis_bins(), and m_edisp.

Referenced by normalize_table(), prob_erecobin(), set_max_edisp(), and table_value().

double GCTAEdisp2D::table_value	(	const int &	base_ll,
		const int &	base_lr,
		const int &	base_rl,
		const int &	base_rr,
		const double &	wgt_el,
		const double &	wgt_er,
		const double &	wgt_tl,
		const double &	wgt_tr,
		const int &	offset
	)		const

private

Return bi-linearly interpolate table value for given migration bin.

Parameters

[in]	base_ll	Base index for left true energy and left offset angle.
[in]	base_lr	Base index for left true energy and right offset angle.
[in]	base_rl	Base index for right true energy and left offset angle.
[in]	base_rr	Base index for right true energy and right offset angle.
[in]	wgt_el	Weighting for left true energy.
[in]	wgt_er	Weighting for right true energy.
[in]	wgt_tl	Weighting for left offset angle.
[in]	wgt_tr	Weighting for right offset angle.
[in]	offset	Offset of migration bin with respect to base indices.

Returns: Bi-linearly interpolate table value.

Definition at line 1777 of file GCTAEdisp2D.cpp.

References m_edisp, and m_inx_matrix.

Referenced by prob_erecobin(), and table_value().

double GCTAEdisp2D::table_value	(	const int &	base_ll,
		const int &	base_lr,
		const int &	base_rl,
		const int &	base_rr,
		const double &	wgt_el,
		const double &	wgt_er,
		const double &	wgt_tl,
		const double &	wgt_tr,
		const double &	migra
	)		const

private

Return bi-linearly interpolate table value for given migration value.

Parameters

[in]	base_ll	Base index for left true energy and left offset angle.
[in]	base_lr	Base index for left true energy and right offset angle.
[in]	base_rl	Base index for right true energy and left offset angle.
[in]	base_rr	Base index for right true energy and right offset angle.
[in]	wgt_el	Weighting for left true energy.
[in]	wgt_er	Weighting for right true energy.
[in]	wgt_tl	Weighting for left offset angle.
[in]	wgt_tr	Weighting for right offset angle.
[in]	migra	Migration value.