Fermi/LAT mean PSF class. More...

#include <GLATMeanPsf.hpp>

Inheritance diagram for GLATMeanPsf:

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

	GLATMeanPsf (const GSkyDir &dir, const GLATObservation &obs)
	PSF constructor. More...

	GLATMeanPsf (const GLATMeanPsf &cube)
	Copy constructor. More...

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

GLATMeanPsf &	operator= (const GLATMeanPsf &cube)
	Assignment operator. More...

double	operator() (const double &offset, const double &logE)
	Return mean PSF*exposure value. More...

void	clear (void)
	Clear mean PSF. More...

GLATMeanPsf *	clone (void) const
	Clone mean PSF. More...

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

int	size (void) const
	Return number of bins in mean PSF. More...

void	set (const GSkyDir &dir, const GLATObservation &obs)
	Compute mean PSF and exposure. More...

int	noffsets (void) const
	Return number of offset bins. More...

int	nenergies (void) const
	Return number of energy bins. More...

const double &	offset (const int &inx) const
	Return offset angle for given bin. More...

const double &	energy (const int &inx) const
	Return energy for given bin. More...

const GSkyDir &	dir (void) const
	Return sky direction for mean PSF. More...

const std::string &	name (void) const
	Return source name for mean PSF. More...

void	name (const std::string &name)
	Set source name for mean PSF. More...

const double &	thetamax (void) const
	Return maximum theta angle. More...

void	thetamax (const double &value)
	Set maximum theta angle. More...

double	psf (const double &offset, const double &logE)
	Return mean PSF value. More...

double	exposure (const double &logE)
	Return exposure value. More...

std::string	print (const GChatter &chatter=NORMAL) const
	Print livetime cube 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 GLATMeanPsf &psf)
	Copy class members. More...

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

void	set_offsets (void)
	Set array of offset values in degrees. More...

void	set_map_corrections (const GLATObservation &obs)
	Compute map corrections. More...

double	integral (const double &radmax, const double &logE)
	Compute integral over PSF. More...

Private Attributes
std::string	m_name
	Source name for mean PSF. More...

GSkyDir	m_dir
	Source direction for mean PSF. More...

std::vector< double >	m_psf
	Mean PSF values. More...

std::vector< double >	m_exposure
	Mean exposure. More...

std::vector< double >	m_mapcorr
	Map corrections. More...

GNodeArray	m_offset
	Offsets of mean PSF. More...

GNodeArray	m_energy
	log10(energy) of mean PSF More...

double	m_theta_max
	Maximum inclination angle (default 70 deg) More...

double	m_last_energy
	Last requested logE value. More...

double	m_last_offset
	Last requested offset value. More...

int	m_inx1_exp
	Exposure index 1. More...

int	m_inx2_exp
	Exposure index 2. More...

int	m_inx1
	Index 1. More...

int	m_inx2
	Index 2. More...

int	m_inx3
	Index 3. More...

int	m_inx4
	Index 4. More...

double	m_wgt1
	Weighting factor 1. More...

double	m_wgt2
	Weighting factor 2. More...

double	m_wgt3
	Weighting factor 3. More...

double	m_wgt4
	Weighting factor 4. More...

Detailed Description

Fermi/LAT mean PSF class.

The position-dependent mean PSF is the point spread function that has been averaged over the zenith and azimuth angles of an observation. The averaging is done using the livetime cube which holds the livetime as function and zenith and azimuth angles for an observation.

Definition at line 51 of file GLATMeanPsf.hpp.

Constructor & Destructor Documentation

GLATMeanPsf::GLATMeanPsf ( void )

Void constructor.

Definition at line 68 of file GLATMeanPsf.cpp.

References init_members().

Referenced by clone().

GLATMeanPsf::GLATMeanPsf	(	const GSkyDir &	dir,
		const GLATObservation &	obs
	)

PSF constructor.

Parameters

[in]	dir	Sky direction.
[in]	obs	LAT observation.

Definition at line 84 of file GLATMeanPsf.cpp.

References init_members(), and set().

GLATMeanPsf::GLATMeanPsf ( const GLATMeanPsf & psf )

Copy constructor.

Parameters

[in] psf Mean PSF.

Definition at line 102 of file GLATMeanPsf.cpp.

References copy_members(), and init_members().

GLATMeanPsf::~GLATMeanPsf ( void )

virtual

Destructor.

Definition at line 118 of file GLATMeanPsf.cpp.

References free_members().

Member Function Documentation

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

inlinevirtual

Return class name.

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

Implements GBase.

Definition at line 124 of file GLATMeanPsf.hpp.

void GLATMeanPsf::clear ( void )

virtual

Clear mean PSF.

Implements GBase.

Definition at line 260 of file GLATMeanPsf.cpp.

References free_members(), and init_members().

GLATMeanPsf * GLATMeanPsf::clone ( void ) const

virtual

Clone mean PSF.

Returns: Pointer to deep copy of mean PSF.

Implements GBase.

Definition at line 278 of file GLATMeanPsf.cpp.

References GLATMeanPsf().

void GLATMeanPsf::copy_members ( const GLATMeanPsf & psf )

private

Copy class members.

Parameters

[in] psf Mean PSF.

Definition at line 633 of file GLATMeanPsf.cpp.

References m_dir, m_energy, m_exposure, m_inx1, m_inx1_exp, m_inx2, m_inx2_exp, m_inx3, m_inx4, m_last_energy, m_last_offset, m_mapcorr, m_name, m_offset, m_psf, m_theta_max, m_wgt1, m_wgt2, m_wgt3, and m_wgt4.

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

const GSkyDir & GLATMeanPsf::dir ( void ) const

inline

Return sky direction for mean PSF.

Returns: Sky direction.

Definition at line 202 of file GLATMeanPsf.hpp.

References m_dir.

Referenced by set().

const double & GLATMeanPsf::energy ( const int & inx ) const

inline

Return energy for given bin.

Parameters

[in] inx Bin index [0,...,nenergies()-1]

Returns: Energy.

Definition at line 190 of file GLATMeanPsf.hpp.

References m_energy.

Referenced by print(), and set().

double GLATMeanPsf::exposure ( const double & logE )

Return exposure value.

Parameters

[in] logE log10 of energy in MeV.

Computes

\[{\rm exposure}(\log E)\]

by linear interpolation, where \(\log E\) is the logarithm of base 10 of the energy in MeV. A zero value is returned if \(\log E\) is not positive.

Definition at line 498 of file GLATMeanPsf.cpp.

References GNodeArray::inx_left(), GNodeArray::inx_right(), m_energy, m_exposure, m_inx1_exp, m_inx2_exp, GNodeArray::set_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

Referenced by set().

void GLATMeanPsf::free_members ( void )

private

Delete class members.

Definition at line 665 of file GLATMeanPsf.cpp.

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

void GLATMeanPsf::init_members ( void )

private

Initialise class members.

< Maximum zenith angle

Definition at line 596 of file GLATMeanPsf.cpp.

References GNodeArray::clear(), GSkyDir::clear(), m_dir, m_energy, m_exposure, m_inx1, m_inx1_exp, m_inx2, m_inx2_exp, m_inx3, m_inx4, m_last_energy, m_last_offset, m_mapcorr, m_name, m_offset, m_psf, m_theta_max, m_wgt1, m_wgt2, m_wgt3, m_wgt4, and set_offsets().

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

double GLATMeanPsf::integral	(	const double &	offsetmax,
		const double &	logE
	)

private

Compute integral over PSF.

Parameters

[in]	offsetmax	Maximum offset angle.
[in]	logE	log10 of energy in MeV.

Definition at line 781 of file GLATMeanPsf.cpp.

References gammalib::deg2rad, GNodeArray::inx_left(), GNodeArray::inx_right(), m_energy, m_offset, m_psf, noffsets(), GNodeArray::set_value(), sin(), GNodeArray::size(), gammalib::twopi, GNodeArray::wgt_left(), and GNodeArray::wgt_right().

Referenced by set_map_corrections().

const std::string & GLATMeanPsf::name ( void ) const

inline

Return source name for mean PSF.

Returns: Source name.

Definition at line 214 of file GLATMeanPsf.hpp.

References m_name.

Referenced by GLATResponse::irf(), GLATResponse::irf_spatial_bin(), name(), and print().

void GLATMeanPsf::name ( const std::string & name )

inline

Set source name for mean PSF.

Parameters

[in] name Source name.

Definition at line 226 of file GLATMeanPsf.hpp.

References m_name, and name().

int GLATMeanPsf::nenergies ( void ) const

inline

Return number of energy bins.

Returns: Number of energy bins.

Definition at line 164 of file GLATMeanPsf.hpp.

References m_energy, and GNodeArray::size().

Referenced by print().

int GLATMeanPsf::noffsets ( void ) const

inline

Return number of offset bins.

Returns: Number of offset bins.

Definition at line 152 of file GLATMeanPsf.hpp.

References m_offset, and GNodeArray::size().

Referenced by integral(), operator()(), print(), and psf().

const double & GLATMeanPsf::offset ( const int & inx ) const

inline

Return offset angle for given bin.

Parameters

[in] inx Bin index [0,...,noffsets()-1]

Returns: Offset angle.

Definition at line 177 of file GLATMeanPsf.hpp.

References m_offset.

Referenced by operator()(), psf(), and set_map_corrections().

double GLATMeanPsf::operator()	(	const double &	offset,
		const double &	logE
	)

Return mean PSF*exposure value.

Parameters

[in]	offset	Angular distance from true source direction (degrees).
[in]	logE	log10 of energy in MeV.

Computes

\[{\rm PSF}(\delta, \log E) \times {\rm exposure}(\log E)\]

by bilinear interpolation, where \(\delta\) is the offset angle from the source direction in degrees, and \(\log E\) is the logarithm of base 10 of the energy in MeV. A zero value is returned if the offset angle is equal or larger than 70 degrees or if \(\log E\) is not positive.

Definition at line 175 of file GLATMeanPsf.cpp.

References GNodeArray::inx_left(), GNodeArray::inx_right(), m_energy, m_exposure, m_inx1, m_inx1_exp, m_inx2, m_inx2_exp, m_inx3, m_inx4, m_mapcorr, m_offset, m_psf, m_wgt1, m_wgt2, m_wgt3, m_wgt4, noffsets(), offset(), GNodeArray::set_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

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

Assignment operator.

Parameters

[in] psf Mean PSF.

Returns: Mean PSF.

Definition at line 140 of file GLATMeanPsf.cpp.

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

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

virtual

Print livetime cube information.

Parameters

[in] chatter Chattiness (defaults to NORMAL).

Returns: String containing ROI information.

Implements GBase.

Definition at line 531 of file GLATMeanPsf.cpp.

References GSkyDir::dec_deg(), energy(), GEnergy::log10MeV(), m_dir, m_energy, m_exposure, m_mapcorr, name(), nenergies(), noffsets(), gammalib::parformat(), GEnergy::print(), GSkyDir::ra_deg(), SILENT, and gammalib::str().

double GLATMeanPsf::psf	(	const double &	offset,
		const double &	logE
	)

Return mean PSF value.

Parameters

[in]	offset	Angular distance from true source direction (degrees).
[in]	logE	log10 of energy in MeV.

Computes

\[{\rm PSF}(\delta, \log E)\]

by bilinear interpolation, where \(\delta\) is the offset angle from the source direction in degrees, and \(\log E\) is the logarithm of base 10 of the energy in MeV. A zero value is returned if the offset angle is equal or larger than 70 degrees or if \(\log E\) is not positive.

Definition at line 411 of file GLATMeanPsf.cpp.

References GNodeArray::inx_left(), GNodeArray::inx_right(), m_energy, m_inx1, m_inx1_exp, m_inx2, m_inx2_exp, m_inx3, m_inx4, m_mapcorr, m_offset, m_psf, m_wgt1, m_wgt2, m_wgt3, m_wgt4, noffsets(), offset(), GNodeArray::set_value(), GNodeArray::wgt_left(), and GNodeArray::wgt_right().

Referenced by set(), and set_map_corrections().

void GLATMeanPsf::set	(	const GSkyDir &	dir,
		const GLATObservation &	obs
	)

Compute mean PSF and exposure.

Parameters

[in]	dir	Source location.
[in]	obs	LAT observation.

Exceptions

GException::invalid_argument No livetime cube found in observation.

Computes the mean PSF and the energy dependent exposure for a source at a given sky location. The PSF is computed for all bin boundaries of the observation, hence if there are N energy bins there will be N+1 energies at which the mean PSF is computed.

Definition at line 298 of file GLATMeanPsf.cpp.

References GLATResponse::aeff(), GNodeArray::append(), GNodeArray::clear(), dir(), GEvents::ebounds(), GEbounds::emax(), GEbounds::emin(), energy(), GObservation::events(), exposure(), G_SET, GEnergy::log10MeV(), GLATObservation::ltcube(), m_dir, m_energy, m_exposure, m_offset, m_psf, psf(), GLATResponse::psf(), GLATObservation::response(), set_map_corrections(), size(), GNodeArray::size(), GEbounds::size(), and GLATResponse::size().

Referenced by GLATMeanPsf().

void GLATMeanPsf::set_map_corrections ( const GLATObservation & obs )

private

Compute map corrections.

Parameters

[in] obs LAT observation.

Sets up a vector of energy dependent corrections that assures that the integral over the PSF in a specific event cube is correctly normalised. For this purpose the PSF is integrated over a radius that fully lies within the event cube and devided by the PSF pixel sum within this radius. The map corrections are mainly important at high energies where the PSF size can become comparable to the pixel size.

See SourceMap::getMapCorrections for the original code in the Fermi/LAT ScienceTools.