EclipticCoordinates
public struct EclipticCoordinates : CustomStringConvertible
The coordinates in the ecliptic (a.k.a. celestial) system, based on solar-system planets orbital planes.
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The celestial longitude
Declaration
Swift
public let celestialLongitude: Degree
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The celestial latitude
Declaration
Swift
public let celestialLatitude: Degree
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The epoch of the coordinates.
Declaration
Swift
public let epoch: Epoch
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The reference equinox.
Declaration
Swift
public let equinox: Equinox
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A convenience accessor for the celestial longitude
Declaration
Swift
public var lambda: Degree { get }
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A convenience accessor for the celestial latitude
Declaration
Swift
public var beta: Degree { get }
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Creates a new EclipticCoordinates instance.
Declaration
Parameters
celestialLongitude
The celestial longitude value
celestialLatitude
The celestial latitude value
epoch
The optional epoch value, default to J2000.0
equinox
The optional equinox, default to standard equinox J2000.0.
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Creates a new EclipticCoordinates instance.
Declaration
Parameters
lambda
The longitude value.
beta
The latitude value
epoch
The optional epoch value, default to J2000.0. It is not called ‘epsilon’ to avoid confusion with equinox.
equinox
The optional equinox, default to standard equinox J2000.0.
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Returns equatorial coordinates corresponding to the current ecliptic ones.
Declaration
Swift
public func makeEquatorialCoordinates() -> EquatorialCoordinates
Return Value
A new equatorial coordinates instance.
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Returns apparent equatorial coordinates corresponding to the current ecliptic ones.
Declaration
Swift
public func makeApparentEquatorialCoordinates() -> EquatorialCoordinates
Return Value
A new equatorial coordinates instance
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Returns EclipticCoordinates precessed to a new given epoch.
Declaration
Swift
public func precessedCoordinates(to newEpoch: Epoch) -> EclipticCoordinates
Parameters
newEpoch
The new epoch to precess to.
Return Value
A new EclipticCoordinates instance
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Return new ecliptic coordinates corrected for the annual aberration of the Earth. It must be used for star coordinates, not planets. See AA, p149.
Declaration
Swift
public func correctedForAnnualAberration(julianDay: JulianDay, highPrecision: Bool = true) -> EclipticCoordinates
Parameters
julianDay
The julian day for which the aberration is computed.
highPrecision
If
false
, the Ron-Vondrák algorithm is used. See AA p.153. Iftrue
, the newer VSOP87 theory is used.OSunReturn Value
Corected ecliptic coordinates of the star.
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Description of EclipticCoordinates
Declaration
Swift
public var description: String { get }