A scalar velocity (if signed) or speed (unsigned). More...

#include <supernovas.h>

Inheritance diagram for supernovas::ScalarVelocity:

Public Member Functions
	ScalarVelocity (double m_per_s)
	Instantiates a (signed) scalar velocity (speed) with the specified S.I.
ScalarVelocity	abs () const
	Returns the magnitude of this speed, as a unsigned speed.
double	au_per_day () const
	Returns this speed in AU/day.
double	beta () const
	Returns this speed (v) as β = v / c.
bool	equals (const ScalarVelocity &speed, const ScalarVelocity &tolerance) const
	Checks if this speed equals the specified other speed within the tolerance.
bool	equals (const ScalarVelocity &speed, double tolerance=Unit::mm/Unit::sec) const
	Checks if this speed equals the specified other speed within the tolerance.
double	Gamma () const
	Returns the relativistic boost parameter Γ for this speed (v) as Γ = &radic (1 - v² / c²).
Velocity	in_direction (const Vector &direction) const
	Returns a 3-dimensional velocity vector corresponding to this speed along the specified direction.
double	km_per_s () const
	Returns this speed in km/s.
double	m_per_s () const
	Returns this speed in m/s.
bool	operator!= (const ScalarVelocity &speed) const
	Checks if this speed differs from the specified other speed, by more than 1 mm/s.
Coordinate	operator* (const Interval &time) const
	Returns the distance travelled at this speed under the specified time interval.
ScalarVelocity	operator+ (const ScalarVelocity &r) const
	Returns the signed scalar sum of this speed and the specified other speed, using the relativistic formula for addition.
ScalarVelocity	operator- (const ScalarVelocity &r) const
	Returns the signed scalar difference of this speed and the specified other speed, using the relativistic formula for addition.
bool	operator== (const ScalarVelocity &speed) const
	Checks if this speed equals the specified other speed within 1 mm/s.
ScalarVelocity	operator[] (int idx) const
double	redshift () const
	Returns this speed as a redshift measure.
std::string	to_string (int decimals=3) const
	Returns a string representation of this speed in km/s with the specified decimal places shown.
Coordinate	travel (const Interval &time) const
	Returns the distance travelled at this speed under the specified time interval.
Coordinate	travel (double seconds) const
	Returns the distance travelled at this speed under the specified time interval.
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 ScalarVelocity	from_redshift (double z)
	Instantiates a new speed instance from a given redshift value.
static const ScalarVelocity &	stationary ()
	Returns a reference to a statically defined zero speed of a stationary object.
static const ScalarVelocity &	undefined ()
	Returns a reference to a static instance of an undefined / invalid scalar velocity.

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 velocity (if signed) or speed (unsigned).

See also: Position ,

Constructor & Destructor Documentation

◆ ScalarVelocity()

supernovas::ScalarVelocity::ScalarVelocity ( double m_per_s )

explicit

Instantiates a (signed) scalar velocity (speed) with the specified S.I.

value in m/s.

Parameters

m_per_s [m/s] the speed

See also: from_redshift()

References supernovas::Validating::_valid, supernovas::Constant::c, and m_per_s().

Member Function Documentation

◆ abs()

ScalarVelocity supernovas::ScalarVelocity::abs ( ) const

Returns the magnitude of this speed, as a unsigned speed.

Returns the unsigned magnitude of this (possibly signed) speed.

Returns: The absolute value of the (possibly signed) speed value represented by this instance.; the absolute value of this (possibly signed) speed.

References supernovas::Validating::is_valid().

◆ au_per_day()

double supernovas::ScalarVelocity::au_per_day ( ) const

Returns this speed in AU/day.

Returns: [AU/day] the speed value.

See also: m_per_s(), km_per_s(), beta(), Gamma(), redshift()

References supernovas::Unit::au, and supernovas::Unit::day.

◆ beta()

double supernovas::ScalarVelocity::beta ( ) const

Returns this speed (v) as β = v / c.

Returns: β = v / c

See also: m_per_s(), km_per_s(), au_per_day(), Gamma(), redshift()

References supernovas::Constant::c.

Referenced by Gamma(), operator+(), and operator-().

◆ equals() [1/2]

bool supernovas::ScalarVelocity::equals	(	const ScalarVelocity &	speed,
		const ScalarVelocity &	tolerance ) const

Checks if this speed equals the specified other speed within the tolerance.

Parameters

speed	the reference speed
tolerance	(optional) tolerance for the comparison (default: 0.001 m/s).

Returns: true if this speed equals the argument within the tolerance, or else false

See also: operator==(), operator!=()

References equals(), and m_per_s().

◆ equals() [2/2]

bool supernovas::ScalarVelocity::equals	(	const ScalarVelocity &	speed,
		double	tolerance = Unit::mm / Unit::sec ) const

Checks if this speed equals the specified other speed within the tolerance.

Parameters

speed	the reference speed
tolerance	[m/s] (optional) tolerance for the comparison (default: 0.001 m/s).

Returns: true if this speed equals the argument within the tolerance, or else false

See also: operator==(), operator!=()

Referenced by equals(), operator!=(), and operator==().

◆ from_redshift()

ScalarVelocity supernovas::ScalarVelocity::from_redshift ( double z )

static

Instantiates a new speed instance from a given redshift value.

Parameters

z	the redshift value.

Returns: a scalar velocity instance corresponding to the specified redshift value.

References supernovas::Validating::is_valid(), supernovas::Unit::km, novas_z2v(), and supernovas::Unit::sec.

◆ Gamma()

double supernovas::ScalarVelocity::Gamma ( ) const

Returns the relativistic boost parameter Γ for this speed (v) as Γ = &radic (1 - v² / c²).

Returns: the relativistic boost Γ = &radic (1 - v² / c²)

See also: m_per_s(), km_per_s(), au_per_day(), redshift()

References beta().

◆ in_direction()

Velocity supernovas::ScalarVelocity::in_direction ( const Vector & direction ) const

Returns a 3-dimensional velocity vector corresponding to this speed along the specified direction.

Parameters

direction a vector specifying the direction. Its magnitude is irrelevant.

Returns: a new velocity vector, in the specified direction and with the magnitude of this speed.

References supernovas::Vector::_array(), supernovas::Vector::abs(), and supernovas::Validating::is_valid().

◆ km_per_s()

double supernovas::ScalarVelocity::km_per_s ( ) const

Returns this speed in km/s.

Returns: [km/s] the speed value.

See also: m_per_s(), au_per_day(), beta(), Gamma(), redshift()

Referenced by supernovas::GeodeticObserver::GeodeticObserver(), redshift(), and to_string().

◆ m_per_s()

double supernovas::ScalarVelocity::m_per_s ( ) const

Returns this speed in m/s.

Returns: [m/s] the speed value.

See also: km_per_s(), au_per_day(), beta(), Gamma(), redshift()

Referenced by ScalarVelocity(), equals(), supernovas::Apparent::from_cirs(), supernovas::Apparent::from_tod(), supernovas::CatalogEntry::radial_velocity(), supernovas::Horizontal::to_apparent(), and supernovas::CatalogEntry::v_lsr().

◆ operator!=()

bool supernovas::ScalarVelocity::operator!= ( const ScalarVelocity & speed ) const

Checks if this speed differs from the specified other speed, by more than 1 mm/s.

Parameters

speed the reference speed

Returns: true if this speed differs from the argument by more than 1 mm/s, or else false

See also: operator==()

References equals().

◆ operator*()

Coordinate supernovas::ScalarVelocity::operator* ( const Interval & time ) const

Returns the distance travelled at this speed under the specified time interval.

Parameters

Time of observation and astronomical timescales the time interval

Returns: the distance travelled

See also: travel()

References supernovas::Validating::is_valid(), and travel().

◆ operator+()

ScalarVelocity supernovas::ScalarVelocity::operator+ ( const ScalarVelocity & r ) const

Returns the signed scalar sum of this speed and the specified other speed, using the relativistic formula for addition.

Parameters

r	the speed on the right-hand side

Returns: the relativistic sum of this speed and the argument.

See also: operator-()

References beta(), supernovas::Constant::c, and supernovas::Validating::is_valid().

◆ operator-()

ScalarVelocity supernovas::ScalarVelocity::operator- ( const ScalarVelocity & r ) const

Returns the signed scalar difference of this speed and the specified other speed, using the relativistic formula for addition.

Parameters

r	the speed on the right-hand side

Returns: the relativistic difference of this speed and the argument.

See also: operator+()

References beta(), supernovas::Constant::c, and supernovas::Validating::is_valid().

◆ operator==()

bool supernovas::ScalarVelocity::operator== ( const ScalarVelocity & speed ) const

Checks if this speed equals the specified other speed within 1 mm/s.

Parameters

speed the reference speed

Returns: true if this speed equals the argument within 1 mm/s, or else false

See also: equals(), operator!=()

References equals().

◆ operator[]()

ScalarVelocity supernovas::ScalarVelocity::operator[] ( int idx ) const

◆ redshift()

double supernovas::ScalarVelocity::redshift ( ) const

Returns this speed as a redshift measure.

Returns: the equivalent redshift measure z.

See also: m_per_s(), km_per_s(), au_per_day(), Gamma()

References km_per_s(), and novas_v2z().

◆ stationary()

const ScalarVelocity & supernovas::ScalarVelocity::stationary ( )

static

Returns a reference to a statically defined zero speed of a stationary object.

Returns: a reference to a static instance of zero speed.

◆ to_string()

std::string supernovas::ScalarVelocity::to_string ( int decimals = 3 ) const

Returns a string representation of this speed in km/s with the specified decimal places shown.

Parameters

decimals (optional) the number of decimal places to print (default: 3)

Returns: a new string containing a representation of this speed.

References km_per_s().

Referenced by supernovas::CatalogEntry::to_string(), and supernovas::Velocity::to_string().

◆ travel() [1/2]

Coordinate supernovas::ScalarVelocity::travel ( const Interval & time ) const

Returns the distance travelled at this speed under the specified time interval.

Parameters

Time of observation and astronomical timescales the time interval

Returns: the distance travelled

See also: operator*(), Velocity::travel()

References supernovas::Interval::seconds(), and travel().

◆ travel() [2/2]

Coordinate supernovas::ScalarVelocity::travel ( double seconds ) const

Returns the distance travelled at this speed under the specified time interval.

Parameters

seconds [s] the time interval

Returns: the distance travelled

See also: operator*(), Velocity::travel()

References supernovas::Validating::is_valid().

Referenced by supernovas::Interval::operator*(), operator*(), and travel().

◆ undefined()

const ScalarVelocity & supernovas::ScalarVelocity::undefined ( )

static

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

Returns: a reference to a standard undefined scalar velocity instance.

Referenced by supernovas::Track< CoordType >::radial_velocity_at().

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ScalarVelocity()

Member Function Documentation

◆ abs()

◆ au_per_day()

◆ beta()

◆ equals() [1/2]

◆ equals() [2/2]

◆ from_redshift()

◆ Gamma()

◆ in_direction()

◆ km_per_s()

◆ m_per_s()

◆ operator!=()

◆ operator*()

◆ operator+()

◆ operator-()

◆ operator==()

◆ operator[]()

◆ redshift()

◆ stationary()

◆ to_string()

◆ travel() [1/2]

◆ travel() [2/2]

◆ undefined()