Interface for the rectangular sky region class. More...

#include <GSkyRegionRectangle.hpp>

Inheritance diagram for GSkyRegionRectangle:

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

	GSkyRegionRectangle (const GSkyDir &centre, const double &width, const double &height, const double &posang)
	Sky direction constructor. More...

	GSkyRegionRectangle (const double &ra, const double &dec, const double &width, const double &height, const double &posang)
	Right Ascension and Declination constructor. More...

	GSkyRegionRectangle (const std::string &line)
	String constructor. More...

	GSkyRegionRectangle (const GSkyRegionRectangle &region)
	Copy constructor. More...

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

GSkyRegionRectangle &	operator= (const GSkyRegionRectangle &region)
	Assignment operator. More...

void	clear (void)
	Clear instance. More...

GSkyRegionRectangle *	clone (void) const
	Clone rectangular sky region. More...

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

const GSkyDir &	centre (void) const
	Return rectangular region centre. More...

void	centre (const GSkyDir &centre)
	Set rectangular region centre. More...

void	centre (const double &ra, const double &dec)
	Set rectangular region centre Right Ascension and Declincation. More...

double	ra (void) const
	Return rectangular region centre Right Ascension. More...

double	dec (void) const
	Return rectangular region centre Declination. More...

const double &	width (void) const
	Return region width extension (in degrees) More...

void	width (const double &width)
	Set width of rectangular region. More...

const double &	height (void) const
	Return region height extension (in degrees) More...

void	height (const double &height)
	Set height of rectangular region. More...

const double &	posang (void) const
	Return region position angle (in degrees) More...

void	posang (const double &posang)
	Set position angle of rectangular region. More...

GSkyDir	corner (const int &index) const
	Return sky direction of one corner of the rectangle. More...

void	read (const std::string &line)
	Read region from DS9 string. More...

std::string	write (void) const
	Write region into a string. More...

bool	contains (const GSkyDir &dir) const
	Checks if sky direction lies within region. More...

bool	contains (const GSkyRegion &reg) const
	Checks if region is fully contained within this region. More...

bool	overlaps (const GSkyRegion &reg) const
	Checks if region is overlapping with this region. More...

std::string	print (const GChatter &chatter=NORMAL) const
	Print rectangular region. More...

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

	GSkyRegion (const GSkyRegion &region)
	Copy constructor. More...

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

virtual GSkyRegion &	operator= (const GSkyRegion &region)
	Assignment operator. More...

const std::string &	type (void) const
	Return region type. More...

const std::string &	name (void) const
	Return region name. More...

const double &	solidangle (void) const
	Return solid angle of region. More...

void	type (const std::string &type)
	Set region type. More...

void	name (const std::string &name)
	Set region name. More...

void	solidangle (const double &solidangle)
	Set solid angle of region. More...

Public Member Functions inherited from GBase
virtual	~GBase (void)
	Destructor. More...

Protected Member Functions
void	init_members (void)
	Initialise class members. More...

void	copy_members (const GSkyRegionRectangle &region)
	Copy class members. More...

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

void	compute_solid_angle (void)
	Compute solid angle of rectangle. More...

bool	contains (const GSkyPixel &local) const
	Checks if local direction lies within region. More...

GSkyPixel	dir_to_local (const GSkyDir &dir) const
	Transform sky direction to local rectangle coordinates. More...

GSkyDir	local_to_dir (const GSkyPixel &local) const
	Transform local rectangle coordinates to sky direction. More...

Protected Member Functions inherited from GSkyRegion
void	init_members (void)
	Initialise class members. More...

void	copy_members (const GSkyRegion &region)
	Copy class members. More...

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

Protected Attributes
GSkyDir	m_centre
	Centre or reference point of the region. More...

double	m_width
	Width of the region (degrees) More...

double	m_height
	Height of the region (degrees) More...

double	m_posang
	Position angle, counterclockwise from North (degrees) More...

Protected Attributes inherited from GSkyRegion
std::string	m_type
	Type of the region (circle, rectangle,...) More...

std::string	m_name
	Name of the region. More...

double	m_solid
	Solid angle subtended by the region (sr) More...

Detailed Description

Interface for the rectangular sky region class.

This class provides an implementation for a rectangular sky region. The sky region is defined by an array of parameters, the meaning of which is specific to the derived class where the region type or shape is defined.

The class holds several properties such as solid angle subtended by the region and computed through internal method compute_solid().

The position angle counts counter-clockwise from celestial North and is aligned with the height axis of the rectangle. Note, that height and width describe the diameter of the region.

Sky directions can be transformed to the local/global coordinate system via the methods transform_to_local() / transform_to_global(). The position (in global coordinates) of the 4 corners of the rectangle can be received via the method get_corner(index).

Definition at line 62 of file GSkyRegionRectangle.hpp.

Constructor & Destructor Documentation

GSkyRegionRectangle::GSkyRegionRectangle ( void )

Void constructor.

Definition at line 62 of file GSkyRegionRectangle.cpp.

References init_members().

Referenced by clone().

GSkyRegionRectangle::GSkyRegionRectangle	(	const GSkyDir &	centre,
		const double &	width,
		const double &	height,
		const double &	posang
	)

Sky direction constructor.

Parameters

[in]	centre	Centre of rectangle.
[in]	width	Region width (degrees).
[in]	height	Region height (degrees).
[in]	posang	Position angle (degrees).

Definition at line 80 of file GSkyRegionRectangle.cpp.

References centre(), compute_solid_angle(), height(), init_members(), posang(), and width().

GSkyRegionRectangle::GSkyRegionRectangle	(	const double &	ra,
		const double &	dec,
		const double &	width,
		const double &	height,
		const double &	posang
	)

Right Ascension and Declination constructor.

Parameters

[in]	ra	Right Ascension of region centre (degrees).
[in]	dec	Declination of region centre (degrees).
[in]	width	Region width (degrees).
[in]	height	Region height (degrees).
[in]	posang	Position angle (degrees).

Definition at line 111 of file GSkyRegionRectangle.cpp.

References centre(), compute_solid_angle(), height(), init_members(), posang(), and width().

GSkyRegionRectangle::GSkyRegionRectangle ( const std::string & line )

explicit

String constructor.

Parameters

[in] line DS9 region file line.

Constructs region from a DS9 region file line.

Definition at line 141 of file GSkyRegionRectangle.cpp.

References init_members(), and read().

GSkyRegionRectangle::GSkyRegionRectangle ( const GSkyRegionRectangle & region )

Copy constructor.

Parameters

[in] region Rectangular sky region.

Definition at line 160 of file GSkyRegionRectangle.cpp.

References copy_members(), and init_members().

GSkyRegionRectangle::~GSkyRegionRectangle ( void )

virtual

Destructor.

Definition at line 177 of file GSkyRegionRectangle.cpp.

References free_members().

Member Function Documentation

const GSkyDir & GSkyRegionRectangle::centre ( void ) const

inline

Return rectangular region centre.

Returns: Region centre.

Returns the region centre.

Definition at line 144 of file GSkyRegionRectangle.hpp.

References m_centre.

Referenced by GSkyRegionRectangle(), read(), and GSkyRegionMap::set_region_rectangle().

void GSkyRegionRectangle::centre ( const GSkyDir & dir )

inline

Set rectangular region centre.

Parameters

[in] dir Region centre.

Sets the centre of the rectangular region to the specified sky direction.

Definition at line 158 of file GSkyRegionRectangle.hpp.

References m_centre.

void GSkyRegionRectangle::centre	(	const double &	ra,
		const double &	dec
	)

inline

Set rectangular region centre Right Ascension and Declincation.

Parameters

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

Sets the centre of the rectangular region to the specified Right Ascension and Declination.

Definition at line 175 of file GSkyRegionRectangle.hpp.

References m_centre, and GSkyDir::radec_deg().

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

inlinevirtual

Return class name.

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

Implements GSkyRegion.

Definition at line 130 of file GSkyRegionRectangle.hpp.

void GSkyRegionRectangle::clear ( void )

virtual

Clear instance.

Implements GSkyRegion.

Definition at line 232 of file GSkyRegionRectangle.cpp.

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

Referenced by read().

GSkyRegionRectangle * GSkyRegionRectangle::clone ( void ) const

virtual

Clone rectangular sky region.

Returns: Deep copy to rectangular sky region.

Implements GSkyRegion.

Definition at line 252 of file GSkyRegionRectangle.cpp.

References GSkyRegionRectangle().

void GSkyRegionRectangle::compute_solid_angle ( void )

protected

Compute solid angle of rectangle.

This method computes the solid angle of the rectangle in steradians and stores the result in the m_solid member.

The solid angle is computed using

\[ \Omega = 2 {\rm width} \sin \left( \frac{\rm height}{2} \right) \]

where \({\rm width}\) and \({\rm height}\) are the width and the height of the rectangle expressed in radians.

Definition at line 861 of file GSkyRegionRectangle.cpp.

References gammalib::deg2rad, m_height, GSkyRegion::m_solid, m_width, and sin().

Referenced by GSkyRegionRectangle(), height(), read(), and width().

bool GSkyRegionRectangle::contains ( const GSkyDir & dir ) const

virtual

Checks if sky direction lies within region.

Parameters

[in] dir Sky direction.

Returns: True if sky direction is contained in region.

A sky direction lies within a region when its distance to the region centre is not larger than the region extension in both axes directions.

Implements GSkyRegion.

Definition at line 491 of file GSkyRegionRectangle.cpp.

References dir_to_local().

Referenced by contains(), and GSkyRegionMap::set_region_rectangle().

bool GSkyRegionRectangle::contains ( const GSkyRegion & reg ) const

virtual

Checks if region is fully contained within this region.

Parameters

[in] reg Sky region.

Returns: True if region is contained in region.

Exceptions

GException::feature_not_implemented Not all region types supported currently.

Implements GSkyRegion.

Definition at line 513 of file GSkyRegionRectangle.cpp.

References abs(), GSkyRegionCircle::centre(), contains(), corner(), dir_to_local(), G_CONTAINS, m_height, m_width, GSkyRegionMap::map(), GSkyRegionMap::nonzero_indices(), gammalib::rad2deg, GSkyRegionCircle::radius(), GSkyRegion::type(), GSkyPixel::x(), and GSkyPixel::y().

bool GSkyRegionRectangle::contains ( const GSkyPixel & local ) const

protected

Checks if local direction lies within region.

Parameters

[in] local Sky direction in local coordinate system.

A local direction lies within a region when its distance to the region centre is not larger than the region extension in both axes directions.

Definition at line 879 of file GSkyRegionRectangle.cpp.

References abs(), contains(), m_height, m_width, gammalib::rad2deg, GSkyPixel::x(), and GSkyPixel::y().

void GSkyRegionRectangle::copy_members ( const GSkyRegionRectangle & region )

protected

Copy class members.

Parameters

[in] region Rectangular sky region.

Definition at line 823 of file GSkyRegionRectangle.cpp.

References m_centre, m_height, m_posang, and m_width.

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

GSkyDir GSkyRegionRectangle::corner ( const int & index ) const

Return sky direction of one corner of the rectangle.

Parameters

[in] index Corner index [0,3]

Returns: Sky direction of corner.

Exceptions

GException::out_of_range Corner index is not in [0,3].

Returns the sky direction of one corner of the rectangle. The corner index is counted counterclockwise from the positive Right Ascension and Declination directions:

index = 0 : \((\alpha + \frac{\rm width}{2}, \delta + \frac{\rm height}{2})\)
index = 1 : \((\alpha + \frac{\rm width}{2}, \delta - \frac{\rm height}{2})\)
index = 2 : \((\alpha - \frac{\rm width}{2}, \delta + \frac{\rm height}{2})\)
index = 3 : \((\alpha - \frac{\rm width}{2}, \delta - \frac{\rm height}{2})\)

where \(\alpha\) and \(\delta\) are the Right Ascension and Declination of the rectangle centre, and \({\rm width}\) and \({\rm height}\) are the width and height of the rectangle.

Definition at line 733 of file GSkyRegionRectangle.cpp.

References gammalib::deg2rad, G_CORNER, local_to_dir(), m_height, and m_width.

Referenced by GSkyRegionCircle::contains(), contains(), and GSkyRegionMap::set_region_rectangle().

double GSkyRegionRectangle::dec ( void ) const

inline

Return rectangular region centre Declination.

Returns: Region centre Declination (degrees).

Returns the region centre Declination in degrees.

Definition at line 204 of file GSkyRegionRectangle.hpp.

References GSkyDir::dec_deg(), and m_centre.

Referenced by print(), and GSkyRegionMap::set_region_rectangle().

GSkyPixel GSkyRegionRectangle::dir_to_local ( const GSkyDir & dir ) const

protected

Transform sky direction to local rectangle coordinates.

Parameters

[in] dir Sky direction.

Returns: Local cartesian region object coordinates.

Transform the sky direction dir to the local cartesian coordinate system. The local coordinates \((x,y)\) are defined by

\[ x = d \sin(\phi) \]

and

\[ y = d \cos(\phi) \]

where \(d\) is the angular distance between the sky direction dir and the centre of the rectangle in radians, and \(\phi\) is the position angle of the sky direction dir with respect to the position angle of the rectangle, computed counter clockwise.

Definition at line 930 of file GSkyRegionRectangle.cpp.

References cos(), gammalib::deg2rad, GSkyDir::dist(), m_centre, m_posang, GSkyDir::posang(), and sin().

Referenced by contains(), and overlaps().

void GSkyRegionRectangle::free_members ( void )

protected

Delete class members.

Definition at line 839 of file GSkyRegionRectangle.cpp.

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

const double & GSkyRegionRectangle::height ( void ) const

inline

Return region height extension (in degrees)

Returns: Region height (degrees).

Returns the region height extension in degrees.

Definition at line 232 of file GSkyRegionRectangle.hpp.

References m_height.

Referenced by GSkyRegionRectangle(), height(), overlaps(), print(), and read().

void GSkyRegionRectangle::height ( const double & height )

Set height of rectangular region.

Parameters

[in] height Rectangle height (degrees).

Exceptions

GException::invalid_argument Height value is less than 0.

Sets the height of the rectangular sky region. Only non-negative heights are allowed.

Note that for a position angle of zero, the height axis is pointing to celestial north.

Definition at line 306 of file GSkyRegionRectangle.cpp.

References compute_solid_angle(), G_HEIGHT, height(), m_height, and gammalib::str().

void GSkyRegionRectangle::init_members ( void )

protected

Initialise class members.

Definition at line 804 of file GSkyRegionRectangle.cpp.

References GSkyDir::clear(), m_centre, m_height, m_posang, GSkyRegion::m_type, and m_width.

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

GSkyDir GSkyRegionRectangle::local_to_dir ( const GSkyPixel & local ) const

protected

Transform local rectangle coordinates to sky direction.

Parameters

[in] local Local rectangle coordinates.

Returns: Sky direction.

Transform the local coordinates local to a sky direction. See GSkyRegionRectangle::dir_to_local for the relation between local rectangle coordinates and the sky direction.

Definition at line 958 of file GSkyRegionRectangle.cpp.

References gammalib::atan2(), gammalib::deg2rad, m_centre, m_posang, gammalib::pihalf, GSkyDir::rotate(), sqrt(), GSkyPixel::x(), and GSkyPixel::y().

Referenced by corner().

GSkyRegionRectangle & GSkyRegionRectangle::operator= ( const GSkyRegionRectangle & region )

Assignment operator.

Parameters

[in] region Rectangular sky region.

Returns: Rectangular sky region.

Definition at line 199 of file GSkyRegionRectangle.cpp.

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

bool GSkyRegionRectangle::overlaps ( const GSkyRegion & reg ) const

virtual

Checks if region is overlapping with this region.

Parameters

[in] reg Sky region.

Returns: True if region overlaps with region.

Exceptions

GException::feature_not_implemented Regions differ in type.

Checks whether a region overlaps with the rectangle.

Todo:: Improve implementation for rectangle-rectangle

Implements GSkyRegion.

Definition at line 625 of file GSkyRegionRectangle.cpp.

References abs(), GSkyRegionCircle::centre(), dir_to_local(), G_CONTAINS, height(), GSkyRegionMap::overlaps(), gammalib::rad2deg, GSkyRegionCircle::radius(), GSkyRegion::type(), width(), GSkyPixel::x(), and GSkyPixel::y().

Referenced by GSkyRegionCircle::overlaps().

const double & GSkyRegionRectangle::posang ( void ) const

inline

Return region position angle (in degrees)

Returns: Region position angle (degrees).

Returns the region position angle in degrees. The position angle is counted counterclockwise from North.

Definition at line 247 of file GSkyRegionRectangle.hpp.

References m_posang.

Referenced by GSkyRegionRectangle(), posang(), print(), and read().

void GSkyRegionRectangle::posang ( const double & posang )

inline

Set position angle of rectangular region.

Parameters

[in] posang Position angle (degrees).

Sets the position angle of the rectangular sky region. The position angle is counted counterclockwise from celestial North and is aligned to the rectangle height.

Definition at line 263 of file GSkyRegionRectangle.hpp.

References m_posang, and posang().

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