com.mhuss.AstroLib

Class Nutation

java.lang.Object

com.mhuss.AstroLib.Nutation

public class Nutation
extends java.lang.Object

Nutation functions and static data.

Based on C code from Bill Gray (www.projectpluto.com)

Constructor Summary

Constructors

Constructor and Description
Nutation() Default constructor.
Nutation(double t) Time only constructor.
Nutation(double t, double dP, double dE) Explicit (all values) constructor.

Method Summary

Modifier and Type	Method and Description
void	calc(double t) Calculate nutation values.
void	calcDeltaEpsilon(double t) Calculate delta Epsilon nutation value only.
void	calcDeltaPhi(double t) Calculate delta Phi nutation value only.
double	getDEpsilon() Delta Epsilon value.
double	getDPhi() Delta Phi value.
static void	main(java.lang.String[] args) (for unit testing only)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Nutation

public Nutation()

Default constructor.

Nutation

public Nutation(double t)

Time only constructor.

Parameters:

t - Time in Julian centuries from J2000.

Nutation

public Nutation(double t,
                double dP,
                double dE)

Explicit (all values) constructor.

Parameters:

t - Time in Julian centuries from J2000.

dP - delta phi value

dE - delta epsilon value

Method Detail

getDPhi

public double getDPhi()

Delta Phi value.

This value represents nutation (delta phi) in arcseconds

Returns:

delta phi value

getDEpsilon

public double getDEpsilon()

Delta Epsilon value.

This value represents nutation (delta epsilon) in arcseconds

Returns:

delta epsilon value

calc

public void calc(double t)

Calculate nutation values.

Either dPhi or dEpsilon can be Astro.INVALID on input, in which case that value is not computed. (we added this because sometimes, you want only dPhi or dEpsilon; in such cases, computing _both_ is a waste of perfectly good CPU time).

Parameters:

t - Time in Julian centuries from J2000.

calcDeltaPhi

public void calcDeltaPhi(double t)

Calculate delta Phi nutation value only.

The current delta Epsilon value is preserved.

Parameters:

t - Time in Julian centuries from J2000.

calcDeltaEpsilon

public void calcDeltaEpsilon(double t)

Calculate delta Epsilon nutation value only.

The current delta Phi value is preserved.

Parameters:

t - Time in Julian centuries from J2000.

main

public static void main(java.lang.String[] args)

(for unit testing only)