supernovas::Coordinate Class Reference

A scalar coordinate or distance between two points in space. More...

#include <supernovas.h>

Inheritance diagram for supernovas::Coordinate:

Public Member Functions
	Coordinate (double meters)
	Instantiates a distance (signed scalar separation along some direction) with the specified value in meters.
Coordinate	abs () const
	Returns the absolute value of this distance.
double	au () const
	Returns the distance in astronomical units.
double	Gpc () const
	Returns the distance in gigaparsecs.
double	km () const
	Returns the distance in kilometers.
double	kpc () const
	Returns the distance in kiloparsecs.
double	lyr () const
	Returns the distance in lightyears.
double	m () const
	Returns the distance in meters.
double	Mpc () const
	Returns the distance in megaparsecs.
ScalarVelocity	operator/ (const Interval &dt) const
	Returns the scalar velocity that is equal to this coordinate travelled under the specified time interval.
Angle	parallax () const
	Returns the parallax angle that corresponds to this distance instance.
double	pc () const
	Returns the distance in parsecs.
std::string	to_string (int decimals=3) const
	Returns a string representation of this distance using the specified number of significant figures and a best matched distance unit, e.g.
Public Member Functions inherited from supernovas::Validating
bool	is_valid () const
	Returns the previously set 'valid' stae of the implementing instance.
	operator bool () const
	Objects that implement Validating can be used in conditionals directly, without explicitly calling is_valid().

Static Public Member Functions
static const Coordinate &	at_Gpc ()
	Returns a standard distance of 1 Gpc.
static Coordinate	from_parallax (const Angle &parallax)
	Returns a new distance instance corresponding to a parallax angle.
static const Coordinate &	undefined ()
	Returns a reference to a static instance of an undefined / invalid coordinate.
static const Coordinate &	zero ()
	Returns a standard zero distance.

Additional Inherited Members
Protected Member Functions inherited from supernovas::Validating
	Validating ()
	dummy constructor;
Protected Attributes inherited from supernovas::Validating
bool	_valid = false
	the state variable.

Detailed Description

A scalar coordinate or distance between two points in space.

See also

Position

Constructor & Destructor Documentation

Coordinate()

supernovas::Coordinate::Coordinate ( double meters )

explicit

Instantiates a distance (signed scalar separation along some direction) with the specified value in meters.

You may use Unit to convert other distance measures to meters. For example, to set a distance of 12.4 parsecs, you might simply write:

Coordinate d(12.4 * Unit::pc);

Parameters

meters

[m] The initializing value.

See also

zero(), at_Gpc()

References supernovas::Validating::_valid.

Member Function Documentation

abs()

Coordinate supernovas::Coordinate::abs

(

)

const

Returns the absolute value of this distance.

Returns

the absolute value (length or distance) for this coordinate, as a coordinate itself.

References supernovas::Validating::is_valid().

at_Gpc()

const Coordinate & supernovas::Coordinate::at_Gpc ( )

static

Returns a standard distance of 1 Gpc.

Historically NOVAS placed sidereal source at 1 Gpc distance if the distance was not specified otherwise. SuperNOVAS follows that, and so this static method can be used to obtain a persistent reference to a 1 Gpc instance.

Returns

A reference to a persistent standard 1 Gpc distance instance.

References supernovas::Unit::Gpc.

au()

double supernovas::Coordinate::au

(

)

const

Returns the distance in astronomical units.

Returns

[AU] the distance in astronomical units.

See also

m(), km(), lyr(), pc(), kpc(), Mpc(), Gpc()

References supernovas::Unit::au.

Referenced by to_string().

from_parallax()

Coordinate supernovas::Coordinate::from_parallax ( const Angle & parallax )

static

Returns a new distance instance corresponding to a parallax angle.

Parameters

parallax

The parallax angle, which defines the distance

Returns

a distance instance corresponding to the specified parallax angle

See also

parallax()

References supernovas::Validating::is_valid(), parallax(), and supernovas::Unit::pc.

Gpc()

double supernovas::Coordinate::Gpc

(

)

const

Returns the distance in gigaparsecs.

Returns

[Gpc] the distance in gigaparsecs.

See also

m(), km(), au(), lyr(), pc(), kpc(), Mpc()

References supernovas::Unit::Gpc.

Referenced by to_string().

km()

double supernovas::Coordinate::km

(

)

const

Returns the distance in kilometers.

Returns

[km] the distance in kilometers.

See also

m(), au(), lyr(), pc(), kpc(), Mpc(), Gpc()

Referenced by to_string().

kpc()

double supernovas::Coordinate::kpc

(

)

const

Returns the distance in kiloparsecs.

Returns

[kpc] the distance in kiloparsecs.

See also

m(), km(), au(), lyr(), pc(), Mpc(), Gpc()

References supernovas::Unit::kpc.

Referenced by to_string().

lyr()

double supernovas::Coordinate::lyr

(

)

const

Returns the distance in lightyears.

Returns

[lyr] the distance in lightyears.

See also

m(), km(), au(), pc(), kpc(), Mpc(), Gpc()

References supernovas::Unit::lyr.

m()

double supernovas::Coordinate::m

(

)

const

Returns the distance in meters.

Returns

[m] the distance in meters.

See also

km(), au(), lyr(), pc(), kpc(), Mpc(), Gpc()

Referenced by supernovas::CatalogEntry::distance(), supernovas::Site::equals(), supernovas::Orbital::from_mean_motion(), supernovas::AstrometricPosition::obs_time(), supernovas::OrbitalSystem::orbit(), supernovas::Horizontal::to_apparent(), and supernovas::Spherical::xyz().

Mpc()

double supernovas::Coordinate::Mpc

(

)

const

Returns the distance in megaparsecs.

Returns

[Mpc] the distance in megaparsecs.

See also

m(), km(), au(), lyr(), pc(), kpc(), Gpc()

References supernovas::Unit::Mpc.

Referenced by to_string().

operator/()

ScalarVelocity supernovas::Coordinate::operator/

(

const Interval &

dt

)

const

Returns the scalar velocity that is equal to this coordinate travelled under the specified time interval.

Parameters

dt	the time interval on the right-hand-side of '/'.

Returns

scalar velocity v = x / dt, where x is this coordinate.

See also

Position::operator/()

References supernovas::Validating::is_valid(), and supernovas::Interval::seconds().

parallax()

Angle supernovas::Coordinate::parallax

(

)

const

Returns the parallax angle that corresponds to this distance instance.

Returns

the parallax angle corresponding to this distance.

See also

from_parallax()

References supernovas::Unit::arcsec, supernovas::Validating::is_valid(), and pc().

Referenced by from_parallax().

pc()

double supernovas::Coordinate::pc

(

)

const

Returns the distance in parsecs.

Returns

[pc] the distance in parsecs.

See also

m(), km(), au(), lyr(), kpc(), Mpc(), Gpc()

References supernovas::Unit::pc.

Referenced by parallax(), and to_string().

to_string()

std::string supernovas::Coordinate::to_string

(

int

decimals = 3

)

const

Returns a string representation of this distance using the specified number of significant figures and a best matched distance unit, e.g.

"10.96 km", or 305.6 pc" etc.

Returns

A human readable string representation of the distance and a unit specifier.

References au(), supernovas::Unit::au, Gpc(), km(), kpc(), Mpc(), pc(), and supernovas::Unit::pc.

Referenced by supernovas::CatalogEntry::to_string(), supernovas::Orbital::to_string(), and supernovas::Position::to_string().

undefined()

const Coordinate & supernovas::Coordinate::undefined ( )

static

Returns a reference to a static instance of an undefined / invalid coordinate.

Returns

a reference to a standard instance of an undefined coordinate.

Referenced by supernovas::Track< CoordType >::distance_at(), and supernovas::Planet::mean_radius().

zero()

const Coordinate & supernovas::Coordinate::zero ( )

static

Returns a standard zero distance.

Returns

A reference to a persistent standard zero distance instance.