coordConv::Coord Class Reference

#include <coord.h>

Public Member Functions
	Coord (double equatAng, double polarAng, double parallax=0)
	Coord (double equatAng, double polarAng, double parallax, double equatPM, double polarPM, double radVel)
	Coord (Eigen::Vector3d const &pos)
	Coord (Eigen::Vector3d const &pos, Eigen::Vector3d const &pm)
	Coord ()
	~Coord ()
bool	atInfinity () const
bool	atPole () const
double	getDistance () const
double	getParallax () const
bool	getSphPos (double &equatAng, double &polarAng) const
bool	getPM (double &equatPM, double &polarPM) const
double	getRadVel () const
Eigen::Vector3d const	getVecPos () const
Eigen::Vector3d const	getVecPM () const
bool	isfinite () const
double	angularSeparation (Coord const &coord) const
double	orientationTo (Coord const &coord) const
Coord	offset (double &toOrient, double fromOrient, double dist) const
bool	operator== (Coord const &rhs)
bool	operator!= (Coord const &rhs)
std::string	__repr__ () const

Detailed Description

Coordinates represent target position and proper motion.

The coordinate system is always right handed, so azimuth is 0 south, 90 east (and hour angle is negated, though it is not visible in very much of the API).

Access is available as spherical coordinates and cartesian vectors.

If parallax < MinParallax / 0.9 then isInfinity() returns true and parallax is reported as 0. Having a lower limit prevents vector operations from overflowing.

Definition at line 27 of file coord.h.

Constructor & Destructor Documentation

coordConv::Coord::Coord ( double  equatAng, double  polarAng, double  parallax = 0  )

explicit

Construct a Coord from spherical position

Parameters

[in]	equatAng	equatorial angle (e.g. RA, Long, Az) (degrees)
[in]	polarAng	polar angle (e.g. Dec, Latitude, Alt) (degrees)
[in]	parallax	parallax (arcsec)

Definition at line 20 of file coord.cc.

coordConv::Coord::Coord ( double  equatAng, double  polarAng, double  parallax, double  equatPM, double  polarPM, double  radVel  )

explicit

Construct a Coord from spherical position and proper motion

Parameters

[in]	equatAng	equatorial angle (e.g. RA, Long, Az) (degrees)
[in]	polarAng	polar angle (e.g. Dec, Latitude, Alt) (degrees)
[in]	parallax	parallax (arcsec)
[in]	equatPM	equatorial proper motion (arcsec/century); this is dEquatAng/dt, so it gets large near the pole
[in]	polarPM	polar proper motion (arcsec/century)
[in]	radVel	radial velocity (km/sec, positive receding)

Definition at line 26 of file coord.cc.

coordConv::Coord::Coord ( Eigen::Vector3d const &  pos )

explicit

Construct a Coord from cartesian position

Parameters

[in]

pos

cartesian position (AU)

Warning

: distance is not constrained

Definition at line 54 of file coord.cc.

coordConv::Coord::Coord ( Eigen::Vector3d const &  pos, Eigen::Vector3d const &  pm  )

explicit

Construct a Coord from cartesian position and velocity

Parameters

[in]	pos	cartesian position (AU)
[in]	pm	cartesian proper motion (AU/year)

Warning

: distance is not constrained

Definition at line 62 of file coord.cc.

coordConv::Coord::Coord ( )

explicit

Construct a Coord with unknown position and proper motion

Definition at line 70 of file coord.cc.

coordConv::Coord::~Coord ( )

inline

Definition at line 73 of file coord.h.

Member Function Documentation

std::string coordConv::Coord::__repr__

(

)

const

Return a string representation

Definition at line 227 of file coord.cc.

double coordConv::Coord::angularSeparation

(

Coord const &

coord

)

const

Compute the angular separation from another coord

Returns

angular separation (deg)

Definition at line 150 of file coord.cc.

bool coordConv::Coord::atInfinity ( ) const

inline

Return true if object is so far away that it is considered to be at infinity

Returns

true if distance is within 90% of MinParallax (includes some slop to handle coordinate conversion that reduce distance slightly).

Definition at line 81 of file coord.h.

bool coordConv::Coord::atPole ( ) const

inline

Return true if so near the pole that equatorial angles cannot be computed

Definition at line 86 of file coord.h.

double coordConv::Coord::getDistance ( ) const

inline

Get distance in AU

Returns

distance, in AU; if atInfinity() then the value is not inf, but will often be approximately AUPerParsec/MinParallax.

Definition at line 94 of file coord.h.

double coordConv::Coord::getParallax

(

)

const

Get parallax in arcsec

Returns

parallax (arcsec), or 0 if atInfinity()

Definition at line 78 of file coord.cc.

bool coordConv::Coord::getPM	(	double &	equatPM,
		double &	polarPM
	)		const

Get proper motion

Parameters

[out]	equatPM	equatorial component of proper motion (e.g. dRA/dt) (arcsec/century)
[out]	polarPM	polar component of proper motion (e.g. dDec/dt) (arcsec/century)

Returns

atPole; if true then equatPM and polarPM are arbitrarily set to 0

Definition at line 98 of file coord.cc.

double coordConv::Coord::getRadVel

(

)

const

Get radial velocity

Returns

radVel: radial velocity (km/sec, positive receding)

Warning

if atInfinity then radVel may be surprisingly changed by a coordinate transformation; you may want to report toRadVel = fromRadVel in that situation

Definition at line 134 of file coord.cc.

bool coordConv::Coord::getSphPos	(	double &	equatAng,
		double &	polarAng
	)		const

Get spherical position

Parameters

[out]	equatAng	equatorial angle (e.g. RA, Long, Az) (degrees)
[out]	polarAng	polar angle (e.g. Dec, Latitude, Alt) (degrees)

Returns

atPole; if true then equatAng is arbitrarily set to 0

Definition at line 82 of file coord.cc.

Eigen::Vector3d const coordConv::Coord::getVecPM ( ) const

inline

Get the cartesian proper motion and radial velocity

Returns

cartesian proper motion and radial velocity (AU/year)

Definition at line 142 of file coord.h.

Eigen::Vector3d const coordConv::Coord::getVecPos ( ) const

inline

Get the cartesian position and velocity

Returns

cartesian position (AU)

Definition at line 135 of file coord.h.

bool coordConv::Coord::isfinite

(

)

const

Test if all values are finite

Definition at line 141 of file coord.cc.

Coord coordConv::Coord::offset	(	double &	toOrient,
		double	fromOrient,
		double	dist
	)		const

Compute a new coord offset from this coord along the arc of a great circle

Parameters

[out]	toOrient	orientation of offset arc at offset position (deg)
[in]	fromOrient	orientation of offset arc at this position (deg)
[in]	dist	offset distance as the length of the arc of a great circle (deg)

Returns

offset coord

Exceptions

runtime_error

if this coord is too near a pole

This diagram may help:

                                                    .
                                              .      тОЮ toOrient
                                        --------------> dir. of increasing equatorial angle at offset coord
                               .    offset coord
                      .
            .
   .         тОЮ fromOrient

-------------—> dir. of increasing equatorial angle at this coord this coord

Definition at line 172 of file coord.cc.

bool coordConv::Coord::operator!= ( Coord const &  rhs )

inline

Definition at line 195 of file coord.h.

bool coordConv::Coord::operator== ( Coord const &  rhs )

inline

Definition at line 191 of file coord.h.

double coordConv::Coord::orientationTo

(

Coord const &

coord

)

const

Compute the orientation of a great circle offset to another coord

In detail: computes the orientation at this point of a great circle connecting this coord to another coord. The orientation is 0 if the great circle lies along the direction of increasing equatorial angle, 90 if it lies along the direction increasing polar angle.

Returns

orientation (deg), or NaN if the angular separation is noo near 0 or 180 degrees

Definition at line 156 of file coord.cc.

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The documentation for this class was generated from the following files:

• include/coordConv/coord.h
• src/coord.cc