Sky direction class. More...

#include <GSkyDir.hpp>

Inheritance diagram for GSkyDir:

Public Member Functions
	GSkyDir (void)
	Constructor. More...

	GSkyDir (const GVector &vector)
	Vector constructor. More...

	GSkyDir (const GSkyDir &dir)
	Copy constructor. More...

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

GSkyDir &	operator= (const GSkyDir &dir)
	Assignment operator. More...

void	clear (void)
	Clear sky direction. More...

GSkyDir *	clone (void) const
	Clone sky direction. More...

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

void	radec (const double &ra, const double &dec)
	Set equatorial sky direction (radians) More...

void	radec_deg (const double &ra, const double &dec)
	Set equatorial sky direction (degrees) More...

void	lb (const double &l, const double &b)
	Set galactic sky direction (radians) More...

void	lb_deg (const double &l, const double &b)
	Set galactic sky direction (degrees) More...

void	celvector (const GVector &vector)
	Set sky direction from 3D vector in celestial coordinates. More...

void	galvector (const GVector &vector)
	Set sky direction from 3D vector in Galactic coordinates. More...

void	rotate (const double &phi, const double &theta)
	Rotate sky direction by zenith and azimuth angle. More...

void	rotate_deg (const double &phi, const double &theta)
	Rotate sky direction by zenith and azimuth angle. More...

void	precess (const double &from_epoch, const double &to_epoch)
	Precess sky direction. More...

void	sun (const GTime &time, const double &epoch=2000.0)
	Set sky direction to direction of Sun. More...

void	moon (const GTime &time, const double &epoch=2000.0)
	Set sky direction to direction of Moon. More...

const double &	l (void) const
	Return galactic longitude in radians. More...

const double &	b (void) const
	Return galactic latitude in radians. More...

const double &	ra (void) const
	Return Right Ascension in radians. More...

const double &	dec (void) const
	Return Declination in radians. More...

double	l_deg (void) const
	Return galactic longitude in degrees. More...

double	b_deg (void) const
	Returns galactic latitude in degrees. More...

double	ra_deg (void) const
	Returns Right Ascension in degrees. More...

double	dec_deg (void) const
	Returns Declination in degrees. More...

GVector	celvector (void) const
	Return sky direction as 3D vector in celestial coordinates. More...

GVector	galvector (void) const
	Return sky direction as 3D vector in galactic coordinates. More...

double	cos_dist (const GSkyDir &dir) const
	Compute cosine of angular distance between sky directions. More...

double	dist (const GSkyDir &dir) const
	Compute angular distance between sky directions in radians. More...

double	dist_deg (const GSkyDir &dir) const
	Compute angular distance between sky directions in degrees. More...

double	posang (const GSkyDir &dir, const std::string &coordsys="CEL") const
	Compute position angle between sky directions in radians. More...

double	posang_deg (const GSkyDir &dir, const std::string &coordsys="CEL") const
	Compute position angle between sky directions in degrees. More...

std::string	print (const GChatter &chatter=NORMAL) const
	Print sky direction 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 GSkyDir &dir)
	Copy class members. More...

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

void	equ2gal (void) const
	Convert equatorial to galactic coordinates. More...

void	gal2equ (void) const
	Convert galactic to equatorial coordinates. More...

void	euler (const int &type, const double &xin, const double &yin, double xout, double yout) const
	General coordinate transformation routine for J2000. More...

Private Attributes
bool	m_has_lb
	Has galactic coordinates. More...

bool	m_has_radec
	Has equatorial coordinates. More...

double	m_l
	Galactic longitude in radians. More...

double	m_b
	Galactic latitude in radians. More...

double	m_ra
	Right Ascension in radians. More...

double	m_dec
	Declination in radians. More...

bool	m_has_lb_cache

bool	m_has_radec_cache

double	m_sin_b

double	m_cos_b

double	m_sin_dec

double	m_cos_dec

Friends
bool	operator== (const GSkyDir &a, const GSkyDir &b)
	Equality operator. More...

bool	operator!= (const GSkyDir &a, const GSkyDir &b)
	Non equality operator. More...

Detailed Description

Sky direction class.

This class implements a spherical coordinate on the sky. Two coordinate systems are supported: celestial (or equatorial), defined by Right Ascension and Declination, and Galactic, defined by galactic longitude and galactic latitude. The class provides automatic conversion between both systems if required. Coordinates are stored in either of the systems (in units of radians), and conversion is performed (and stored) if requested. Coordinates can be given and returned in radians or in degrees. Note that the epoch for celestial coordinates is fixed to J2000.

Definition at line 62 of file GSkyDir.hpp.

Constructor & Destructor Documentation

GSkyDir::GSkyDir ( void )

Constructor.

Definition at line 60 of file GSkyDir.cpp.

References init_members().

Referenced by clone().

GSkyDir::GSkyDir ( const GVector & vector )

explicit

Vector constructor.

Parameters

[in] vector Sky vector.

Constructs a sky direction from a 3-element celestial vector. See the celvector() method for more information.

Definition at line 78 of file GSkyDir.cpp.

References celvector(), and init_members().

GSkyDir::GSkyDir ( const GSkyDir & dir )

Copy constructor.

Parameters

[in] dir Sky direction.

Definition at line 96 of file GSkyDir.cpp.

References copy_members(), and init_members().

GSkyDir::~GSkyDir ( void )

virtual

Destructor.

Definition at line 112 of file GSkyDir.cpp.

References free_members().

Member Function Documentation

const double & GSkyDir::b ( void ) const

inline

Return galactic latitude in radians.

Returns: Galactic latitude in radians.

Definition at line 187 of file GSkyDir.hpp.

References equ2gal(), m_b, m_has_lb, and m_has_radec.

Referenced by b_deg(), cos_dist(), cta_psf_radial_kerns_delta::cta_psf_radial_kerns_delta(), GHealpix::dir2pix(), equ2gal(), euler(), GHealpix::interpolator(), lb(), operator==(), posang(), and precess().

double GSkyDir::b_deg ( void ) const

inline

Returns galactic latitude in degrees.

Returns: Galactic latitude in degrees.

Definition at line 202 of file GSkyDir.hpp.

References b(), and gammalib::rad2deg.

Referenced by GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), and GWcs::dir2pix().

void GSkyDir::celvector ( const GVector & vector )

Set sky direction from 3D vector in celestial coordinates.

Parameters

[in] vector 3D vector.

Convert a 3-dimensional vector in celestial coordinates into a sky direction. The transformation is given by

\[ \alpha = \arctan \left( \frac{x_1}{x_0} \right) \]

\[ \delta = \arcsin x_2 \]

Definition at line 313 of file GSkyDir.cpp.

References asin(), gammalib::atan2(), m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, and m_ra.

Referenced by com_radial_kerns_omega::eval(), com_elliptical_kerns_omega::eval(), cta_nroi_radial_kern_omega::eval(), cta_nroi_elliptical_kern_omega::eval(), cta_irf_diffuse_kern_phi::eval(), cta_nroi_diffuse_kern_phi::eval(), cta_psf_diffuse_kern_phi::eval(), GEphemerides::geo2ssb(), GCTAPointing::instdir(), GCTAPointing::skydir(), GWcs::solidangle(), GCOMBvc::tdelta(), and GCOMBvcs::tdelta().

GVector GSkyDir::celvector ( void ) const

Return sky direction as 3D vector in celestial coordinates.

Returns: Sky direction as 3D vector in celestial coordinates.

Definition at line 957 of file GSkyDir.cpp.

References cos(), gal2equ(), m_cos_dec, m_dec, m_has_lb, m_has_radec, m_has_radec_cache, m_ra, m_sin_dec, and sin().

Referenced by GSkyDir(), precess(), and rotate().

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

inlinevirtual

Return class name.

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

Implements GBase.

Definition at line 148 of file GSkyDir.hpp.

void GSkyDir::clear ( void )

virtual

GSkyDir * GSkyDir::clone ( void ) const

virtual

Clone sky direction.

Returns: Pointer to deep copy of sky direction.

Implements GBase.

Definition at line 182 of file GSkyDir.cpp.

References GSkyDir().

void GSkyDir::copy_members ( const GSkyDir & dir )

private

Copy class members.

Parameters

[in] dir Sky direction.

Definition at line 1294 of file GSkyDir.cpp.

References m_b, m_cos_b, m_cos_dec, m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, m_l, m_ra, m_sin_b, and m_sin_dec.

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

double GSkyDir::cos_dist ( const GSkyDir & dir ) const

Compute cosine of angular distance between sky directions.

Parameters

[in] dir Sky direction to which cosine of distance is to be computed.

Returns: Cosine of angular distance.

Computes the cosine of the angular distance between two sky directions in radians.

Definition at line 1027 of file GSkyDir.cpp.

References b(), cos(), dec(), l(), m_b, m_cos_b, m_cos_dec, m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, m_l, m_ra, m_sin_b, m_sin_dec, ra(), and sin().

Referenced by dist().

const double & GSkyDir::dec ( void ) const

inline

Return Declination in radians.

Returns: Declination in radians.

Definition at line 241 of file GSkyDir.hpp.

References gal2equ(), m_dec, m_has_lb, and m_has_radec.

Referenced by cos_dist(), cta_psf_radial_kerns_delta::cta_psf_radial_kerns_delta(), dec_deg(), GHealpix::dir2pix(), gal2equ(), GCOMInstDir::hash(), GLATInstDir::hash(), GSPIInstDir::hash(), GCTAInstDir::hash(), GHealpix::interpolator(), moon(), operator==(), posang(), radec(), and sun().

double GSkyDir::dec_deg ( void ) const

inline

Returns Declination in degrees.

Returns: Declination in degrees.

Definition at line 256 of file GSkyDir.hpp.

References dec(), and gammalib::rad2deg.

Referenced by GSkyRegionCircle::dec(), GSkyRegionRectangle::dec(), GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), GWcs::dir2pix(), GLATResponse::irf(), GCOMResponse::irf_elliptical(), GResponse::irf_elliptical(), GCOMResponse::irf_radial(), GResponse::irf_radial(), GCTAResponseIrf::nroi_elliptical(), GCTAResponseIrf::nroi_radial(), GPulsarEphemeris::print(), GSPIInstDir::print(), GPhoton::print(), GLATMeanPsf::print(), GCTAInstDir::print(), GCTAResponseCube::psf_diffuse(), GCTAPointing::update(), GCTAPointing::write(), GSkyRegionCircle::write(), GCTAEventList::write(), GSkyRegionRectangle::write(), and GCTAObservation::write_attributes().

double GSkyDir::dist ( const GSkyDir & dir ) const

inline

Compute angular distance between sky directions in radians.

Parameters

[in] dir Sky direction to which distance is to be computed.

Returns: Angular distance (radians).

Computes the angular distance between two sky directions in radians.

Definition at line 271 of file GSkyDir.hpp.

References gammalib::acos(), and cos_dist().

Referenced by GCTAOnOffObservation::compute_arf_cut(), GCTAOnOffObservation::compute_rmf(), GModelSpatialRadialProfile::contains(), GModelSpatialRadialGauss::contains(), GModelSpatialRadialDisk::contains(), GModelSpatialRadialGeneralGauss::contains(), GModelSpatialRadialRing::contains(), GModelSpatialEllipticalDisk::contains(), GModelSpatialEllipticalGauss::contains(), GModelSpatialEllipticalGeneralGauss::contains(), GModelSpatialPointSource::contains(), GModelSpatialRadialShell::contains(), GSkyRegionRectangle::dir_to_local(), dist_deg(), GModelSpatialElliptical::eval(), GModelSpatialRadial::eval(), GCTACubeExposure::fill_cube(), GCTACubePsf::fill_cube(), GCTACubeEdisp::fill_cube(), GModelSpatial::flux(), GCTAPointing::instdir(), GCTAResponseIrf::irf(), GCTAResponseCube::irf(), GCTAResponseIrf::irf_diffuse(), GCOMResponse::irf_elliptical(), GCTAResponseCube::irf_elliptical(), GCTAResponseIrf::irf_elliptical(), GCOMResponse::irf_radial(), GCTAResponseCube::irf_radial(), GCTAResponseIrf::irf_radial(), GCTAModelAeffBackground::mc(), GCTAResponseIrf::mc(), GCTAResponseIrf::nirf(), GCTAResponseIrf::npsf(), operator!=(), operator==(), GSkyRegionMap::set_region_rectangle(), GCTABackground3D::solid_angle(), GCTABackground2D::solid_angle(), GWcs::solidangle(), and GSkyMap::solidangle().

double GSkyDir::dist_deg ( const GSkyDir & dir ) const

inline

Compute angular distance between sky directions in degrees.

Parameters

[in] dir Sky direction to which distance is to be computed.

Returns: Angular distance (degrees).

Computes the angular distance between two sky directions in degrees.

Definition at line 286 of file GSkyDir.hpp.

References dist(), and gammalib::rad2deg.

Referenced by GCOMDri::compute_dre(), GCOMDri::cone_content(), GModelSpatialDiffuseMap::contains(), GModelSpatialDiffuseCube::contains(), GSkyRegionCircle::contains(), GModelSpatialPointSource::eval(), GCOMResponse::irf(), GCOMResponse::irf_ptsrc(), GLATResponse::irf_spatial_bin(), GLATEventCube::maxrad(), GModelSky::mc(), GModelSpatialDiffuseMap::mc_cone(), GModelSpatialDiffuseCube::mc_cone(), GModelSpatialPointSource::mc_norm(), GModelSpatialElliptical::mc_norm(), GModelSpatialRadial::mc_norm(), GSkyRegionCircle::overlaps(), GCOMEventList::read_events(), GSkyMap::region_circle(), GSkyRegionMap::set_region_circle(), and GCOMOad::theta().

void GSkyDir::equ2gal ( void ) const

private

Convert equatorial to galactic coordinates.

Definition at line 1332 of file GSkyDir.cpp.

References b(), euler(), l(), m_b, m_dec, m_has_lb, m_l, and m_ra.

Referenced by b(), galvector(), and l().

void GSkyDir::euler	(	const int &	type,
		const double &	xin,
		const double &	yin,
		double *	xout,
		double *	yout
	)		const

private

General coordinate transformation routine for J2000.

Parameters

[in]	type	Conversion type (0=equ2gal, 1=gal2equ)
[in]	xin	Input longitude (RA or GLON) in radians.
[in]	yin	Input latitude (Dec or GLAT) in radians.
[out]	xout	Output longitude in radians.
[out]	yout	Output latitude in radians.

Definition at line 1382 of file GSkyDir.cpp.

References asin(), gammalib::atan2(), b(), cos(), gammalib::fourpi, gammalib::modulo(), sin(), and gammalib::twopi.

Referenced by equ2gal(), and gal2equ().

void GSkyDir::free_members ( void )

private

Delete class members.

Definition at line 1322 of file GSkyDir.cpp.

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

void GSkyDir::gal2equ ( void ) const

private

Convert galactic to equatorial coordinates.

Definition at line 1354 of file GSkyDir.cpp.

References dec(), euler(), m_b, m_dec, m_has_radec, m_l, m_ra, and ra().

Referenced by celvector(), dec(), ra(), and rotate().

void GSkyDir::galvector ( const GVector & vector )

Set sky direction from 3D vector in Galactic coordinates.

Parameters

[in] vector 3D vector.

Convert a 3-dimensional vector in galactic coordinates into a sky direction. The transformation is given by

\[ l = \arctan \left( \frac{x_1}{x_0} \right) \]

\[ b = \arcsin x_2 \]

Definition at line 348 of file GSkyDir.cpp.

References asin(), gammalib::atan2(), m_b, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, and m_l.

GVector GSkyDir::galvector ( void ) const

Return sky direction as 3D vector in galactic coordinates.

Returns: Sky direction as 3D vector in galactic coordinates.

Definition at line 990 of file GSkyDir.cpp.

References cos(), equ2gal(), m_b, m_cos_b, m_has_lb, m_has_lb_cache, m_has_radec, m_l, m_sin_b, and sin().

void GSkyDir::init_members ( void )

private

Initialise class members.

Definition at line 1264 of file GSkyDir.cpp.

References m_b, m_cos_b, m_cos_dec, m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, m_l, m_ra, m_sin_b, and m_sin_dec.

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

const double & GSkyDir::l ( void ) const

inline

Return galactic longitude in radians.

Returns: Galactic longitude in radians.

Definition at line 160 of file GSkyDir.hpp.

References equ2gal(), m_has_lb, m_has_radec, and m_l.

Referenced by cos_dist(), cta_psf_radial_kerns_delta::cta_psf_radial_kerns_delta(), GHealpix::dir2pix(), equ2gal(), GHealpix::interpolator(), l_deg(), lb(), operator==(), and posang().

double GSkyDir::l_deg ( void ) const

inline

Return galactic longitude in degrees.

Returns: Galactic longitude in degrees.

Definition at line 175 of file GSkyDir.hpp.

References l(), and gammalib::rad2deg.

Referenced by GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), and GWcs::dir2pix().

void GSkyDir::lb	(	const double &	l,
		const double &	b
	)

Set galactic sky direction (radians)

Parameters

[in]	l	Galactic longitude in radians.
[in]	b	Galactic latitude in radians.

Sets Galactic longitude and latitude in radians.

Definition at line 251 of file GSkyDir.cpp.

References b(), l(), m_b, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, and m_l.

Referenced by GHealpix::loc2dir(), GHealpix::pix2dir(), and GCOMEventList::read_events().

void GSkyDir::lb_deg	(	const double &	l,
		const double &	b
	)

Set galactic sky direction (degrees)

Parameters

[in]	l	Galactic longitude in degrees.
[in]	b	Galactic latitude in degrees.

Sets Galactic longitude and latitude in degrees.

Definition at line 278 of file GSkyDir.cpp.

References gammalib::deg2rad, m_b, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, and m_l.

Referenced by GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), GWcs::pix2dir(), GCTAPointing::read(), GSkyRegionCircle::read(), GSkyRegionRectangle::read(), and GCOMEventList::read_events().

void GSkyDir::moon	(	const GTime &	time,
		const double &	epoch = `2000.0`
	)

Set sky direction to direction of Moon.

Parameters

[in]	time	Time.
[in]	epoch	Julian epoch.

Sets the sky direction to the direction of the Moon at a given time.

The equations are derived from the Chapront ELP2000/82 Lunar Theory (Chapront-Touze' and Chapront, 1983, 124, 50), as described by Jean Meeus in Chapter 47 of ``Astronomical Algorithms'' (Willmann-Bell, Richmond), 2nd edition, 1998. Meeus quotes an approximate accuracy of 10 arcsec in longitude and 4 arcsec in latitude, but he does not give the time range for this accuracy.

The method was compared to the results obtained using PyEphem for the period 2000 - 2050. Differences in Right Ascension and Declination are always smaller than 0.015 degrees, corresponding to about 1 arcmin. The differences increase over time, meaning that the largest distances are reached by the end of the period.

Definition at line 598 of file GSkyDir.cpp.

References abs(), asin(), gammalib::atan2(), cos(), dec(), gammalib::deg2rad, GTime::jd(), GTime::julian_epoch(), precess(), ra(), gammalib::rad2deg, radec_deg(), sin(), and tan().

GSkyDir & GSkyDir::operator= ( const GSkyDir & dir )

Assignment operator.

Parameters

[in] dir Sky direction.

Returns: Sky direction.

Definition at line 134 of file GSkyDir.cpp.

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

double GSkyDir::posang	(	const GSkyDir &	dir,
		const std::string &	coordsys = `"CEL"`
	)		const

Compute position angle between sky directions in radians.

Parameters

[in]	dir	Sky direction.
[in]	coordsys	Coordinate system ("CEL" or "GAL")

Returns: Position angle (rad).

Computes the position angle of a specified sky direction with respect to the sky direction of the instance in radians. If "CEL" is specified as coordsys the position angle is counted counterclockwise from celestial North, if "GAL" is specified the position angle is counted counterclockwise from Galactic North.

If coordsys is "CEL" the position angle is computed using

\[PA = \arctan \left( \frac{\sin( \alpha - \alpha_0 )} {\cos \delta_0 \tan \delta - \sin \delta_0 \cos(\alpha - \alpha_0)} \right)\]

where

\((\alpha_0,\delta_0)\) are the celestial coordinates of the instance, and
\((\alpha,\delta)\) are the celestial coordinates of sky direction.

If coordsys is "GAL" the position angle is computed using

\[PA = \arctan \left( \frac{\sin( \l - \l_0 )} {\cos \b_0 \tan \b - \sin \b_0 \cos(\l - \l_0)} \right)\]

where

\((\l_0,\l_0)\) are the Galactic coordinates of the instance, and
\((\l,\b)\) are the Galactic coordinates of sky direction.

Definition at line 1151 of file GSkyDir.cpp.

References gammalib::atan2(), b(), cos(), dec(), G_POSANG, l(), m_cos_b, m_cos_dec, m_has_lb_cache, m_has_radec_cache, m_sin_b, m_sin_dec, ra(), sin(), and tan().

Referenced by GCTAOnOffObservation::compute_arf_cut(), GCTAOnOffObservation::compute_rmf(), GSkyRegionRectangle::dir_to_local(), GModelSpatialElliptical::eval(), GCTAPointing::instdir(), GCTAResponseCube::irf_elliptical(), GCTAResponseIrf::irf_elliptical(), GCTAResponseIrf::nroi_elliptical(), GCTAResponseIrf::nroi_radial(), posang_deg(), GSPIResponse::set_cache(), and GSkyRegionMap::set_region_rectangle().

double GSkyDir::posang_deg	(	const GSkyDir &	dir,
		const std::string &	coordsys = `"CEL"`
	)		const

inline

Compute position angle between sky directions in degrees.

Parameters

[in]	dir	Sky direction.
[in]	coordsys	Coordinate system ("CEL" or "GAL")

Returns: Position angle (deg).

Computes the position angle of a specified sky direction with respect to the sky direction of the instance in degrees. If "CEL" is specified as coordsys the position angle is counted counterclockwise from celestial North, if "GAL" is specified the position angle is counted counterclockwise from Galactic North.

See the posang() method for more information about the computation of the position angle.

Definition at line 309 of file GSkyDir.hpp.

References posang(), and gammalib::rad2deg.

Referenced by GCOMOad::phi().

void GSkyDir::precess	(	const double &	from_epoch,
		const double &	to_epoch
	)

Precess sky direction.

Parameters

[in]	from_epoch	Epoch of the current coordinate.
[in]	to_epoch	Epoch of the returned precessed coordinate.

Precesses the sky direction from one epoch to another.

The method is adapted from a set of fortran subroutines based on (a) pages 30-34 of the Explanatory Supplement to the AE, (b) Lieske, et al. (1977) A&A 58, 1-16, and (c) Lieske (1979) A&A 73, 282-284.

Definition at line 451 of file GSkyDir.cpp.

References b(), celvector(), cos(), gammalib::pi, and sin().

Referenced by moon(), and sun().

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

virtual

Print sky direction information.

Parameters

[in] chatter Chattiness.

Returns: String containing sky direction information.

Implements GBase.

Definition at line 1227 of file GSkyDir.cpp.

References m_b, m_dec, m_has_lb, m_has_radec, m_l, m_ra, gammalib::rad2deg, SILENT, and gammalib::str().

Referenced by GCOMInstDir::print(), GModelSpatialDiffuseMap::print(), and GCTAEventCube::print().

const double & GSkyDir::ra ( void ) const

inline

Return Right Ascension in radians.

Returns: Right Ascension in radians.

Definition at line 214 of file GSkyDir.hpp.

References gal2equ(), m_has_lb, m_has_radec, and m_ra.

Referenced by cos_dist(), cta_psf_radial_kerns_delta::cta_psf_radial_kerns_delta(), GHealpix::dir2pix(), gal2equ(), GCOMInstDir::hash(), GLATInstDir::hash(), GSPIInstDir::hash(), GCTAInstDir::hash(), GHealpix::interpolator(), moon(), operator==(), posang(), ra_deg(), radec(), and sun().

double GSkyDir::ra_deg ( void ) const

inline

Returns Right Ascension in degrees.

Returns: Right Ascension in degrees.

Definition at line 229 of file GSkyDir.hpp.

References ra(), and gammalib::rad2deg.

Referenced by GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), GWcs::dir2pix(), GLATResponse::irf(), GCOMResponse::irf_elliptical(), GResponse::irf_elliptical(), GCOMResponse::irf_radial(), GResponse::irf_radial(), GCTAResponseIrf::nroi_elliptical(), GCTAResponseIrf::nroi_radial(), GPulsarEphemeris::print(), GSPIInstDir::print(), GPhoton::print(), GLATMeanPsf::print(), GCTAInstDir::print(), GCTAResponseCube::psf_diffuse(), GSkyRegionCircle::ra(), GSkyRegionRectangle::ra(), GCTAPointing::update(), GCTAPointing::write(), GSkyRegionCircle::write(), GCTAEventList::write(), GSkyRegionRectangle::write(), and GCTAObservation::write_attributes().

void GSkyDir::radec	(	const double &	ra,
		const double &	dec
	)

Set equatorial sky direction (radians)

Parameters

[in]	ra	Right Ascension in radians.
[in]	dec	Declination in radians.

Sets Right Ascension and Declination in radians.

Definition at line 197 of file GSkyDir.cpp.

References dec(), m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, m_ra, and ra().

Referenced by GHealpix::loc2dir(), GHealpix::pix2dir(), GCOMOads::read(), GCTABackground3D::solid_angle(), and GCTABackground2D::solid_angle().

void GSkyDir::radec_deg	(	const double &	ra,
		const double &	dec
	)

Set equatorial sky direction (degrees)

Parameters

[in]	ra	Right Ascension in degrees.
[in]	dec	Declination in degrees.

Sets Right Ascension and Declination in degrees.

Definition at line 224 of file GSkyDir.cpp.

References gammalib::deg2rad, m_dec, m_has_lb, m_has_lb_cache, m_has_radec, m_has_radec_cache, and m_ra.

Referenced by GSkyRegionCircle::centre(), GSkyRegionRectangle::centre(), GCOMDri::compute_dre(), GCOMDri::compute_drg(), GModelSpatialElliptical::dir(), GModelSpatialRadial::dir(), GModelSpatialPointSource::dir(), GPulsar::load_fermi(), GPulsar::load_integral(), GPulsar::load_parfile(), GPulsar::load_psrtime(), moon(), GWcs::pix2dir(), GCTAPointing::read(), GCTAEventList::read(), GSkyRegionCircle::read(), GSkyRegionRectangle::read(), GCTAObservation::read_attributes(), GCTAEventCube::read_cntmap(), gammalib::read_ds_roi(), GCTAEventList::read_events(), GSPIEventCube::read_pnt(), and sun().

void GSkyDir::rotate	(	const double &	phi,
		const double &	theta
	)

Rotate sky direction by zenith and azimuth angle.

Parameters

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

Rotate sky direction by a zenith and azimuth angle given in the system of the sky direction and aligned in celestial coordinates. The azimuth angle is counted counter clockwise from celestial north (this is identical to the astronomical definition of a position angle).

Definition at line 378 of file GSkyDir.cpp.

References celvector(), cos(), GMatrix::eulery(), GMatrix::eulerz(), gal2equ(), m_dec, m_has_lb, m_has_radec, m_ra, gammalib::rad2deg, and sin().

Referenced by GModelSpatial::circle_int_kern_omega::eval(), GCOMResponse::irf_diffuse(), GSkyRegionRectangle::local_to_dir(), and rotate_deg().

void GSkyDir::rotate_deg	(	const double &	phi,
		const double &	theta
	)

Rotate sky direction by zenith and azimuth angle.

Parameters

[in]	phi	Azimuth angle (deg).
[in]	theta	Zenith angle (deg).

Rotate sky direction by a zenith and azimuth angle given in the system of the sky direction and aligned in celestial coordinates. The azimuth angle is counted counter clockwise from celestial north (this is identical to the astronomical definition of a position angle).

Definition at line 424 of file GSkyDir.cpp.

References gammalib::deg2rad, and rotate().

void GSkyDir::sun	(	const GTime &	time,
		const double &	epoch = `2000.0`
	)

Set sky direction to direction of Sun.

Parameters

[in]	time	Time.
[in]	epoch	Julian epoch.

Sets the sky direction to the direction of the Sun at a given time.

The equations were taken from the Astronomical Almanac. They calculate the apparent coordinates of the Sun to a precision of about 0.01 degrees (36 arcsec), for dates between 1950 and 2050.

See https://en.wikipedia.org/wiki/Position_of_the_Sun

Definition at line 528 of file GSkyDir.cpp.

References asin(), gammalib::atan2(), cos(), dec(), gammalib::deg2rad, GTime::jd(), GTime::julian_epoch(), precess(), ra(), gammalib::rad2deg, radec_deg(), and sin().