com.mhuss.AstroLib

Class LunarCalc

java.lang.Object

com.mhuss.AstroLib.LunarCalc

public class LunarCalc
extends java.lang.Object

LunarCalc is a class that does lunar calculations that do not directly depend on the lunar fundamentals (although some do need to call functions in Lunar).

The code in this class also uses other classes outside of Lunar (and some of these classes in turn use Lunar), so these functions are in a separate class, to avoid circular dependencies.

Based in part on C code by Bill Gray (www.projectpluto.com)

Field Summary

Fields

Modifier and Type	Field and Description
static double	SYNODIC_MONTH Exact number of days from one new moon to the next new moon.

Constructor Summary

Constructors

Constructor and Description
LunarCalc()

Method Summary

Modifier and Type	Method and Description
static double	ageOfMoonInDays() Calculate the present age of the moon in days.
static double	ageOfMoonInDays(double jd) Calculate the age of the moon in days for the given Julian day.
static double	ageOfMoonInDays(java.util.GregorianCalendar cal) Calculate the age of the moon in days for the given Calendar instance.
static int	lunation() Calculate the lunation at the present time.
static int	lunation(java.util.GregorianCalendar cal) Calculate the lunation for specified GregorianCalendar instance.
static int	lunation(long jd) Calculate the lunation for specified Julian day.
static void	main(java.lang.String[] args) (for unit testing only)
static double	quarterChange(double jd, ObsInfo loc) Calculate the relatively exact time of the lunar quarter change (NM, 1Q, FM, or 3Q).
static java.lang.String	summary(ObsInfo oi) Build a current lunar information summary String.
static java.lang.String	summaryPHL() Build a current lunar information summary String for Phila, PA, USA (a shameless convenience function for dvaa.org).

Methods inherited from class java.lang.Object

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

Field Detail

SYNODIC_MONTH

public static final double SYNODIC_MONTH

Exact number of days from one new moon to the next new moon.

See Also:

Constant Field Values

Constructor Detail

LunarCalc

public LunarCalc()

Method Detail

ageOfMoonInDays

public static double ageOfMoonInDays(double jd)

Calculate the age of the moon in days for the given Julian day.

Parameters:

jd - - Julian day for which lunar age is required

Returns:

The lunar age in days (0.0 to 29.5306)

ageOfMoonInDays

public static double ageOfMoonInDays(java.util.GregorianCalendar cal)

Calculate the age of the moon in days for the given Calendar instance.

Parameters:

cal - - java.util.GregorianCalendar holding date for which lunar age is required

Returns:

The lunar age in days (0.0 to 29.5306)

ageOfMoonInDays

public static double ageOfMoonInDays()

Calculate the present age of the moon in days.

Returns:

The lunar age in days (0.0 to 29.5306)

lunation

public static int lunation(long jd)

Calculate the lunation for specified Julian day.

A "lunation" is E. W. Brown's numbered series of lunar cycles. Lunation 1 was on January 16, 1923.

Parameters:

jd - Julian day

Returns:

Lunation number

lunation

public static int lunation(java.util.GregorianCalendar cal)

Calculate the lunation for specified GregorianCalendar instance.

A "lunation" is E. W. Brown's numbered series of lunar cycles. Lunation 1 was on January 16, 1923.

Parameters:

cal - java.util.GregorianCalendar to use

Returns:

Lunation number

lunation

public static int lunation()

Calculate the lunation at the present time.

A "lunation" is E. W. Brown's numbered series of lunar cycles. Lunation 1 was on January 16, 1923.

Returns:

Lunation number

summary

public static java.lang.String summary(ObsInfo oi)

Build a current lunar information summary String.

The summary contains the lunation, age in days, rise, and set times.

Parameters:

oi - - The observer's location

Returns:

The summary string

summaryPHL

public static java.lang.String summaryPHL()

Build a current lunar information summary String for Phila, PA, USA (a shameless convenience function for dvaa.org).

The default summary contains the lunation, age in days, rise, and set times for Philadelphia, PA, USA as the observer's location.

Returns:

The summary string

quarterChange

public static double quarterChange(double jd,
                                   ObsInfo loc)

Calculate the relatively exact time of the lunar quarter change (NM, 1Q, FM, or 3Q).

Input must be less than one day before the exact change

Parameters:

jd - Approximate Julian day number of change

loc - Observer location

Returns:

The relatively exact time

main

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

(for unit testing only)