1280 lines
45 KiB
C++
1280 lines
45 KiB
C++
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/************************************************************************
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* Copyright (C) 1996-2003, International Business Machines Corporation *
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* and others. All Rights Reserved. *
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************************************************************************
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* 2003-nov-07 srl Port from Java
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*/
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#ifndef ASTRO_H
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#define ASTRO_H
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#include "unicode/utypes.h"
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#if !UCONFIG_NO_FORMATTING
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#include "gregoimp.h" // for Math
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#include "stdio.h" // for sprintf
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#include "unicode/unistr.h"
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/**
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* <code>CalendarAstronomer</code> is a class that can perform the calculations to
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* determine the positions of the sun and moon, the time of sunrise and
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* sunset, and other astronomy-related data. The calculations it performs
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* are in some cases quite complicated, and this utility class saves you
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* the trouble of worrying about them.
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* <p>
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* The measurement of time is a very important part of astronomy. Because
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* astronomical bodies are constantly in motion, observations are only valid
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* at a given moment in time. Accordingly, each <code>CalendarAstronomer</code>
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* object has a <code>time</code> property that determines the date
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* and time for which its calculations are performed. You can set and
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* retrieve this property with {@link #setDate setDate}, {@link #getDate getDate}
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* and related methods.
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* <p>
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* Almost all of the calculations performed by this class, or by any
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* astronomer, are approximations to various degrees of accuracy. The
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* calculations in this class are mostly modelled after those described
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* in the book
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* <a href="http://www.amazon.com/exec/obidos/ISBN=0521356997" target="_top">
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* Practical Astronomy With Your Calculator</a>, by Peter J.
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* Duffett-Smith, Cambridge University Press, 1990. This is an excellent
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* book, and if you want a greater understanding of how these calculations
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* are performed it a very good, readable starting point.
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* <p>
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* <strong>WARNING:</strong> This class is very early in its development, and
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* it is highly likely that its API will change to some degree in the future.
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* At the moment, it basically does just enough to support {@link IslamicCalendar}
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* and {@link ChineseCalendar}.
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*
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* @author Laura Werner
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* @author Alan Liu
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* @internal
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*/
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class U_I18N_API CalendarAstronomer {
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public:
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// some classes
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public:
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/**
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* Represents the position of an object in the sky relative to the ecliptic,
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* the plane of the earth's orbit around the Sun.
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* This is a spherical coordinate system in which the latitude
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* specifies the position north or south of the plane of the ecliptic.
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* The longitude specifies the position along the ecliptic plane
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* relative to the "First Point of Aries", which is the Sun's position in the sky
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* at the Vernal Equinox.
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* <p>
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* Note that Ecliptic objects are immutable and cannot be modified
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* once they are constructed. This allows them to be passed and returned by
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* value without worrying about whether other code will modify them.
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*
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* @see CalendarAstronomer.Equatorial
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* @see CalendarAstronomer.Horizon
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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class Ecliptic {
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public:
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/**
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* Constructs an Ecliptic coordinate object.
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* <p>
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* @param lat The ecliptic latitude, measured in radians.
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* @param lon The ecliptic longitude, measured in radians.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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Ecliptic(double lat, double lon) {
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latitude = lat;
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longitude = lon;
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}
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/**
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* Return a string representation of this object
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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UnicodeString toString() {
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char tmp[800];
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sprintf(tmp, "[%.5f,%.5f]", longitude*RAD_DEG, latitude*RAD_DEG);
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return UnicodeString(tmp);
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}
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/**
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* The ecliptic latitude, in radians. This specifies an object's
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* position north or south of the plane of the ecliptic,
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* with positive angles representing north.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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double latitude;
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/**
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* The ecliptic longitude, in radians.
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* This specifies an object's position along the ecliptic plane
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* relative to the "First Point of Aries", which is the Sun's position
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* in the sky at the Vernal Equinox,
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* with positive angles representing east.
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* <p>
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* A bit of trivia: the first point of Aries is currently in the
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* constellation Pisces, due to the precession of the earth's axis.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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double longitude;
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};
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/**
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* Represents the position of an
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* object in the sky relative to the plane of the earth's equator.
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* The <i>Right Ascension</i> specifies the position east or west
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* along the equator, relative to the sun's position at the vernal
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* equinox. The <i>Declination</i> is the position north or south
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* of the equatorial plane.
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* <p>
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* Note that Equatorial objects are immutable and cannot be modified
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* once they are constructed. This allows them to be passed and returned by
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* value without worrying about whether other code will modify them.
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*
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* @see CalendarAstronomer.Ecliptic
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* @see CalendarAstronomer.Horizon
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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class Equatorial {
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public:
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/**
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* Constructs an Equatorial coordinate object.
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* <p>
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* @param asc The right ascension, measured in radians.
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* @param dec The declination, measured in radians.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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Equatorial(double asc, double dec)
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: ascension(asc), declination(dec) { }
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/**
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* Return a string representation of this object, with the
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* angles measured in degrees.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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UnicodeString toString() const {
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char tmp[400];
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sprintf(tmp, "%f,%f",
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(ascension*RAD_DEG), (declination*RAD_DEG));
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return UnicodeString(tmp);
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}
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/**
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* Return a string representation of this object with the right ascension
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* measured in hours, minutes, and seconds.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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//String toHmsString() {
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//return radToHms(ascension) + "," + radToDms(declination);
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//}
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/**
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* The right ascension, in radians.
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* This is the position east or west along the equator
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* relative to the sun's position at the vernal equinox,
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* with positive angles representing East.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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double ascension;
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/**
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* The declination, in radians.
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* This is the position north or south of the equatorial plane,
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* with positive angles representing north.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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double declination;
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};
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/**
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* Represents the position of an object in the sky relative to
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* the local horizon.
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* The <i>Altitude</i> represents the object's elevation above the horizon,
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* with objects below the horizon having a negative altitude.
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* The <i>Azimuth</i> is the geographic direction of the object from the
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* observer's position, with 0 representing north. The azimuth increases
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* clockwise from north.
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* <p>
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* Note that Horizon objects are immutable and cannot be modified
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* once they are constructed. This allows them to be passed and returned by
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* value without worrying about whether other code will modify them.
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*
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* @see CalendarAstronomer.Ecliptic
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* @see CalendarAstronomer.Equatorial
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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class Horizon {
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public:
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/**
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* Constructs a Horizon coordinate object.
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* <p>
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* @param alt The altitude, measured in radians above the horizon.
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* @param azim The azimuth, measured in radians clockwise from north.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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Horizon(double alt, double azim)
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: altitude(alt), azimuth(azim) { }
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/**
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* Return a string representation of this object, with the
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* angles measured in degrees.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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UnicodeString toString() {
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char tmp[800];
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sprintf(tmp, "[%.5f,%.5f]", altitude*RAD_DEG, azimuth*RAD_DEG);
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return UnicodeString(tmp);
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}
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/**
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* The object's altitude above the horizon, in radians.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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const double altitude;
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/**
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* The object's direction, in radians clockwise from north.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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const double azimuth;
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};
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public:
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//-------------------------------------------------------------------------
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// Astronomical constants
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//-------------------------------------------------------------------------
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/**
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* The number of standard hours in one sidereal day.
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* Approximately 24.93.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double SIDEREAL_DAY;
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/**
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* The number of sidereal hours in one mean solar day.
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* Approximately 24.07.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double SOLAR_DAY;
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/**
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* The average number of solar days from one new moon to the next. This is the time
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* it takes for the moon to return the same ecliptic longitude as the sun.
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* It is longer than the sidereal month because the sun's longitude increases
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* during the year due to the revolution of the earth around the sun.
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* Approximately 29.53.
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*
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* @see #SIDEREAL_MONTH
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double SYNODIC_MONTH;
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/**
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* The average number of days it takes
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* for the moon to return to the same ecliptic longitude relative to the
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* stellar background. This is referred to as the sidereal month.
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* It is shorter than the synodic month due to
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* the revolution of the earth around the sun.
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* Approximately 27.32.
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*
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* @see #SYNODIC_MONTH
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double SIDEREAL_MONTH;
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/**
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* The average number number of days between successive vernal equinoxes.
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* Due to the precession of the earth's
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* axis, this is not precisely the same as the sidereal year.
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* Approximately 365.24
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*
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* @see #SIDEREAL_YEAR
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double TROPICAL_YEAR;
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/**
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* The average number of days it takes
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* for the sun to return to the same position against the fixed stellar
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* background. This is the duration of one orbit of the earth about the sun
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* as it would appear to an outside observer.
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* Due to the precession of the earth's
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* axis, this is not precisely the same as the tropical year.
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* Approximately 365.25.
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*
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* @see #TROPICAL_YEAR
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double SIDEREAL_YEAR;
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//-------------------------------------------------------------------------
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// Time-related constants
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//-------------------------------------------------------------------------
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/**
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* The number of milliseconds in one second.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const int32_t SECOND_MS;
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/**
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* The number of milliseconds in one minute.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const int32_t MINUTE_MS;
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/**
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* The number of milliseconds in one hour.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const int32_t HOUR_MS;
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/**
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* The number of milliseconds in one day.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double DAY_MS;
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/**
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* The start of the julian day numbering scheme used by astronomers, which
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* is 1/1/4713 BC (Julian), 12:00 GMT. This is given as the number of milliseconds
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* since 1/1/1970 AD (Gregorian), a negative number.
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* Note that julian day numbers and
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* the Julian calendar are <em>not</em> the same thing. Also note that
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* julian days start at <em>noon</em>, not midnight.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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static const double JULIAN_EPOCH_MS;
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// static {
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// Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
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// cal.clear();
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// cal.set(cal.ERA, 0);
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// cal.set(cal.YEAR, 4713);
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// cal.set(cal.MONTH, cal.JANUARY);
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// cal.set(cal.DATE, 1);
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// cal.set(cal.HOUR_OF_DAY, 12);
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// System.out.println("1.5 Jan 4713 BC = " + cal.getTime().getTime());
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// cal.clear();
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// cal.set(cal.YEAR, 2000);
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// cal.set(cal.MONTH, cal.JANUARY);
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// cal.set(cal.DATE, 1);
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// cal.add(cal.DATE, -1);
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// System.out.println("0.0 Jan 2000 = " + cal.getTime().getTime());
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// }
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/**
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* Milliseconds value for 0.0 January 2000 AD.
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*/
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static const double EPOCH_2000_MS;
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//-------------------------------------------------------------------------
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// Assorted private data used for conversions
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//-------------------------------------------------------------------------
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// My own copies of these so compilers are more likely to optimize them away
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static const double PI;
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static const double PI2;
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static const double RAD_HOUR;
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static const double DEG_RAD;
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static const double RAD_DEG;
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//-------------------------------------------------------------------------
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// Constructors
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//-------------------------------------------------------------------------
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/**
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* Construct a new <code>CalendarAstronomer</code> object that is initialized to
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* the current date and time.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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CalendarAstronomer();
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/**
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* Construct a new <code>CalendarAstronomer</code> object that is initialized to
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* the specified date and time.
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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CalendarAstronomer(UDate d);
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/**
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* Construct a new <code>CalendarAstronomer</code> object with the given
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* latitude and longitude. The object's time is set to the current
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* date and time.
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* <p>
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* @param longitude The desired longitude, in <em>degrees</em> east of
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* the Greenwich meridian.
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*
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* @param latitude The desired latitude, in <em>degrees</em>. Positive
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* values signify North, negative South.
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*
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* @see java.util.Date#getTime()
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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CalendarAstronomer(double longitude, double latitude);
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~CalendarAstronomer();
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//-------------------------------------------------------------------------
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// Time and date getters and setters
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//-------------------------------------------------------------------------
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/**
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* Set the current date and time of this <code>CalendarAstronomer</code> object. All
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* astronomical calculations are performed based on this time setting.
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*
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* @param aTime the date and time, expressed as the number of milliseconds since
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* 1/1/1970 0:00 GMT (Gregorian).
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*
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* @see #setDate
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* @see #getTime
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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void setTime(UDate aTime);
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/**
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* Set the current date and time of this <code>CalendarAstronomer</code> object. All
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* astronomical calculations are performed based on this time setting.
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*
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* @param aTime the date and time, expressed as the number of milliseconds since
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* 1/1/1970 0:00 GMT (Gregorian).
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*
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* @see #getTime
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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void setDate(UDate aDate) { setTime(aDate); }
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/**
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* Set the current date and time of this <code>CalendarAstronomer</code> object. All
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* astronomical calculations are performed based on this time setting.
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*
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* @param jdn the desired time, expressed as a "julian day number",
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* which is the number of elapsed days since
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* 1/1/4713 BC (Julian), 12:00 GMT. Note that julian day
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* numbers start at <em>noon</em>. To get the jdn for
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* the corresponding midnight, subtract 0.5.
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*
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* @see #getJulianDay
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* @see #JULIAN_EPOCH_MS
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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void setJulianDay(double jdn);
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/**
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* Get the current time of this <code>CalendarAstronomer</code> object,
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* represented as the number of milliseconds since
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* 1/1/1970 AD 0:00 GMT (Gregorian).
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*
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* @see #setTime
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* @see #getDate
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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UDate getTime();
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/**
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* Get the current time of this <code>CalendarAstronomer</code> object,
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* expressed as a "julian day number", which is the number of elapsed
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* days since 1/1/4713 BC (Julian), 12:00 GMT.
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*
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* @see #setJulianDay
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* @see #JULIAN_EPOCH_MS
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* @internal
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* @deprecated ICU 2.4. This class may be removed or modified.
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*/
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double getJulianDay();
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|
|
|
/**
|
|
* Return this object's time expressed in julian centuries:
|
|
* the number of centuries after 1/1/1900 AD, 12:00 GMT
|
|
*
|
|
* @see #getJulianDay
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getJulianCentury();
|
|
|
|
/**
|
|
* Returns the current Greenwich sidereal time, measured in hours
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getGreenwichSidereal();
|
|
|
|
private:
|
|
double getSiderealOffset();
|
|
public:
|
|
/**
|
|
* Returns the current local sidereal time, measured in hours
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getLocalSidereal();
|
|
|
|
/**
|
|
* Converts local sidereal time to Universal Time.
|
|
*
|
|
* @param lst The Local Sidereal Time, in hours since sidereal midnight
|
|
* on this object's current date.
|
|
*
|
|
* @return The corresponding Universal Time, in milliseconds since
|
|
* 1 Jan 1970, GMT.
|
|
*/
|
|
//private:
|
|
double lstToUT(double lst);
|
|
|
|
Equatorial* eclipticToEquatorial(Ecliptic& ecliptic);
|
|
|
|
/**
|
|
* Convert from ecliptic to equatorial coordinates.
|
|
*
|
|
* @param eclipLong The ecliptic longitude
|
|
* @param eclipLat The ecliptic latitude
|
|
*
|
|
* @return The corresponding point in equatorial coordinates.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
Equatorial* eclipticToEquatorial(double eclipLong, double eclipLat);
|
|
|
|
/**
|
|
* Convert from ecliptic longitude to equatorial coordinates.
|
|
*
|
|
* @param eclipLong The ecliptic longitude
|
|
*
|
|
* @return The corresponding point in equatorial coordinates.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
Equatorial* eclipticToEquatorial(double eclipLong);
|
|
|
|
/**
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
Horizon* eclipticToHorizon(double eclipLong);
|
|
|
|
//-------------------------------------------------------------------------
|
|
// The Sun
|
|
//-------------------------------------------------------------------------
|
|
|
|
//
|
|
// Parameters of the Sun's orbit as of the epoch Jan 0.0 1990
|
|
// Angles are in radians (after multiplying by PI/180)
|
|
//
|
|
static const double JD_EPOCH;
|
|
|
|
static const double SUN_ETA_G;
|
|
static const double SUN_OMEGA_G;
|
|
static const double SUN_E ;
|
|
//double sunR0 = 1.495585e8; // Semi-major axis in KM
|
|
//double sunTheta0 = 0.533128 * PI/180; // Angular diameter at R0
|
|
|
|
// The following three methods, which compute the sun parameters
|
|
// given above for an arbitrary epoch (whatever time the object is
|
|
// set to), make only a small difference as compared to using the
|
|
// above constants. E.g., Sunset times might differ by ~12
|
|
// seconds. Furthermore, the eta-g computation is befuddled by
|
|
// Duffet-Smith's incorrect coefficients (p.86). I've corrected
|
|
// the first-order coefficient but the others may be off too - no
|
|
// way of knowing without consulting another source.
|
|
|
|
// /**
|
|
// * Return the sun's ecliptic longitude at perigee for the current time.
|
|
// * See Duffett-Smith, p. 86.
|
|
// * @return radians
|
|
// */
|
|
// private double getSunOmegaG() {
|
|
// double T = getJulianCentury();
|
|
// return (281.2208444 + (1.719175 + 0.000452778*T)*T) * DEG_RAD;
|
|
// }
|
|
|
|
// /**
|
|
// * Return the sun's ecliptic longitude for the current time.
|
|
// * See Duffett-Smith, p. 86.
|
|
// * @return radians
|
|
// */
|
|
// private double getSunEtaG() {
|
|
// double T = getJulianCentury();
|
|
// //return (279.6966778 + (36000.76892 + 0.0003025*T)*T) * DEG_RAD;
|
|
// //
|
|
// // The above line is from Duffett-Smith, and yields manifestly wrong
|
|
// // results. The below constant is derived empirically to match the
|
|
// // constant he gives for the 1990 EPOCH.
|
|
// //
|
|
// return (279.6966778 + (-0.3262541582718024 + 0.0003025*T)*T) * DEG_RAD;
|
|
// }
|
|
|
|
// /**
|
|
// * Return the sun's eccentricity of orbit for the current time.
|
|
// * See Duffett-Smith, p. 86.
|
|
// * @return double
|
|
// */
|
|
// private double getSunE() {
|
|
// double T = getJulianCentury();
|
|
// return 0.01675104 - (0.0000418 + 0.000000126*T)*T;
|
|
// }
|
|
|
|
/**
|
|
* The longitude of the sun at the time specified by this object.
|
|
* The longitude is measured in radians along the ecliptic
|
|
* from the "first point of Aries," the point at which the ecliptic
|
|
* crosses the earth's equatorial plane at the vernal equinox.
|
|
* <p>
|
|
* Currently, this method uses an approximation of the two-body Kepler's
|
|
* equation for the earth and the sun. It does not take into account the
|
|
* perturbations caused by the other planets, the moon, etc.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getSunLongitude();
|
|
|
|
/**
|
|
* TODO Make this public when the entire class is package-private.
|
|
*/
|
|
/*public*/ void getSunLongitude(double julianDay, double &longitude, double &meanAnomaly);
|
|
|
|
/**
|
|
* The position of the sun at this object's current date and time,
|
|
* in equatorial coordinates.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
Equatorial* getSunPosition();
|
|
|
|
public:
|
|
class SolarLongitude {
|
|
public:
|
|
SolarLongitude(double l)
|
|
: value(l) { }
|
|
double value;
|
|
};
|
|
|
|
public:
|
|
/**
|
|
* Constant representing the vernal equinox.
|
|
* For use with {@link #getSunTime getSunTime}.
|
|
* Note: In this case, "vernal" refers to the northern hemisphere's seasons.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const SolarLongitude VERNAL_EQUINOX;
|
|
|
|
/**
|
|
* Constant representing the summer solstice.
|
|
* For use with {@link #getSunTime getSunTime}.
|
|
* Note: In this case, "summer" refers to the northern hemisphere's seasons.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const SolarLongitude SUMMER_SOLSTICE;
|
|
|
|
/**
|
|
* Constant representing the autumnal equinox.
|
|
* For use with {@link #getSunTime getSunTime}.
|
|
* Note: In this case, "autumn" refers to the northern hemisphere's seasons.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const SolarLongitude AUTUMN_EQUINOX;
|
|
|
|
/**
|
|
* Constant representing the winter solstice.
|
|
* For use with {@link #getSunTime getSunTime}.
|
|
* Note: In this case, "winter" refers to the northern hemisphere's seasons.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const SolarLongitude WINTER_SOLSTICE;
|
|
|
|
/**
|
|
* Find the next time at which the sun's ecliptic longitude will have
|
|
* the desired value.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate getSunTime(UDate desired, UBool next);
|
|
/**
|
|
* Find the next time at which the sun's ecliptic longitude will have
|
|
* the desired value.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate getSunTime(const SolarLongitude& desired, UBool next);
|
|
|
|
/**
|
|
* Returns the time (GMT) of sunrise or sunset on the local date to which
|
|
* this calendar is currently set.
|
|
*
|
|
* NOTE: This method only works well if this object is set to a
|
|
* time near local noon. Because of variations between the local
|
|
* official time zone and the geographic longitude, the
|
|
* computation can flop over into an adjacent day if this object
|
|
* is set to a time near local midnight.
|
|
*
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate getSunRiseSet(UBool rise);
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// //-------------------------------------------------------------------------
|
|
// // Alternate Sun Rise/Set
|
|
// // See Duffett-Smith p.93
|
|
// //-------------------------------------------------------------------------
|
|
//
|
|
// // This yields worse results (as compared to USNO data) than getSunRiseSet().
|
|
// /**
|
|
// * TODO Make this public when the entire class is package-private.
|
|
// */
|
|
// /*public*/ long getSunRiseSet2(boolean rise) {
|
|
// // 1. Calculate coordinates of the sun's center for midnight
|
|
// double jd = Math.floor(getJulianDay() - 0.5) + 0.5;
|
|
// double[] sl = getSunLongitude(jd);
|
|
// double lambda1 = sl[0];
|
|
// Equatorial pos1 = eclipticToEquatorial(lambda1, 0);
|
|
//
|
|
// // 2. Add ... to lambda to get position 24 hours later
|
|
// double lambda2 = lambda1 + 0.985647*DEG_RAD;
|
|
// Equatorial pos2 = eclipticToEquatorial(lambda2, 0);
|
|
//
|
|
// // 3. Calculate LSTs of rising and setting for these two positions
|
|
// double tanL = Math.tan(fLatitude);
|
|
// double H = Math.acos(-tanL * Math.tan(pos1.declination));
|
|
// double lst1r = (PI2 + pos1.ascension - H) * 24 / PI2;
|
|
// double lst1s = (pos1.ascension + H) * 24 / PI2;
|
|
// H = Math.acos(-tanL * Math.tan(pos2.declination));
|
|
// double lst2r = (PI2-H + pos2.ascension ) * 24 / PI2;
|
|
// double lst2s = (H + pos2.ascension ) * 24 / PI2;
|
|
// if (lst1r > 24) lst1r -= 24;
|
|
// if (lst1s > 24) lst1s -= 24;
|
|
// if (lst2r > 24) lst2r -= 24;
|
|
// if (lst2s > 24) lst2s -= 24;
|
|
//
|
|
// // 4. Convert LSTs to GSTs. If GST1 > GST2, add 24 to GST2.
|
|
// double gst1r = lstToGst(lst1r);
|
|
// double gst1s = lstToGst(lst1s);
|
|
// double gst2r = lstToGst(lst2r);
|
|
// double gst2s = lstToGst(lst2s);
|
|
// if (gst1r > gst2r) gst2r += 24;
|
|
// if (gst1s > gst2s) gst2s += 24;
|
|
//
|
|
// // 5. Calculate GST at 0h UT of this date
|
|
// double t00 = utToGst(0);
|
|
//
|
|
// // 6. Calculate GST at 0h on the observer's longitude
|
|
// double offset = Math.round(fLongitude*12/PI); // p.95 step 6; he _rounds_ to nearest 15 deg.
|
|
// double t00p = t00 - offset*1.002737909;
|
|
// if (t00p < 0) t00p += 24; // do NOT normalize
|
|
//
|
|
// // 7. Adjust
|
|
// if (gst1r < t00p) {
|
|
// gst1r += 24;
|
|
// gst2r += 24;
|
|
// }
|
|
// if (gst1s < t00p) {
|
|
// gst1s += 24;
|
|
// gst2s += 24;
|
|
// }
|
|
//
|
|
// // 8.
|
|
// double gstr = (24.07*gst1r-t00*(gst2r-gst1r))/(24.07+gst1r-gst2r);
|
|
// double gsts = (24.07*gst1s-t00*(gst2s-gst1s))/(24.07+gst1s-gst2s);
|
|
//
|
|
// // 9. Correct for parallax, refraction, and sun's diameter
|
|
// double dec = (pos1.declination + pos2.declination) / 2;
|
|
// double psi = Math.acos(Math.sin(fLatitude) / Math.cos(dec));
|
|
// double x = 0.830725 * DEG_RAD; // parallax+refraction+diameter
|
|
// double y = Math.asin(Math.sin(x) / Math.sin(psi)) * RAD_DEG;
|
|
// double delta_t = 240 * y / Math.cos(dec) / 3600; // hours
|
|
//
|
|
// // 10. Add correction to GSTs, subtract from GSTr
|
|
// gstr -= delta_t;
|
|
// gsts += delta_t;
|
|
//
|
|
// // 11. Convert GST to UT and then to local civil time
|
|
// double ut = gstToUt(rise ? gstr : gsts);
|
|
// //System.out.println((rise?"rise=":"set=") + ut + ", delta_t=" + delta_t);
|
|
// long midnight = DAY_MS * (time / DAY_MS); // Find UT midnight on this day
|
|
// return midnight + (long) (ut * 3600000);
|
|
// }
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// /**
|
|
// * Convert local sidereal time to Greenwich sidereal time.
|
|
// * Section 15. Duffett-Smith p.21
|
|
// * @param lst in hours (0..24)
|
|
// * @return GST in hours (0..24)
|
|
// */
|
|
// double lstToGst(double lst) {
|
|
// double delta = fLongitude * 24 / PI2;
|
|
// return normalize(lst - delta, 24);
|
|
// }
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// /**
|
|
// * Convert UT to GST on this date.
|
|
// * Section 12. Duffett-Smith p.17
|
|
// * @param ut in hours
|
|
// * @return GST in hours
|
|
// */
|
|
// double utToGst(double ut) {
|
|
// return normalize(getT0() + ut*1.002737909, 24);
|
|
// }
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// /**
|
|
// * Convert GST to UT on this date.
|
|
// * Section 13. Duffett-Smith p.18
|
|
// * @param gst in hours
|
|
// * @return UT in hours
|
|
// */
|
|
// double gstToUt(double gst) {
|
|
// return normalize(gst - getT0(), 24) * 0.9972695663;
|
|
// }
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// double getT0() {
|
|
// // Common computation for UT <=> GST
|
|
//
|
|
// // Find JD for 0h UT
|
|
// double jd = Math.floor(getJulianDay() - 0.5) + 0.5;
|
|
//
|
|
// double s = jd - 2451545.0;
|
|
// double t = s / 36525.0;
|
|
// double t0 = 6.697374558 + (2400.051336 + 0.000025862*t)*t;
|
|
// return t0;
|
|
// }
|
|
|
|
// Commented out - currently unused. ICU 2.6, Alan
|
|
// //-------------------------------------------------------------------------
|
|
// // Alternate Sun Rise/Set
|
|
// // See sci.astro FAQ
|
|
// // http://www.faqs.org/faqs/astronomy/faq/part3/section-5.html
|
|
// //-------------------------------------------------------------------------
|
|
//
|
|
// // Note: This method appears to produce inferior accuracy as
|
|
// // compared to getSunRiseSet().
|
|
//
|
|
// /**
|
|
// * TODO Make this public when the entire class is package-private.
|
|
// */
|
|
// /*public*/ long getSunRiseSet3(boolean rise) {
|
|
//
|
|
// // Compute day number for 0.0 Jan 2000 epoch
|
|
// double d = (double)(time - EPOCH_2000_MS) / DAY_MS;
|
|
//
|
|
// // Now compute the Local Sidereal Time, LST:
|
|
// //
|
|
// double LST = 98.9818 + 0.985647352 * d + /*UT*15 + long*/
|
|
// fLongitude*RAD_DEG;
|
|
// //
|
|
// // (east long. positive). Note that LST is here expressed in degrees,
|
|
// // where 15 degrees corresponds to one hour. Since LST really is an angle,
|
|
// // it's convenient to use one unit---degrees---throughout.
|
|
//
|
|
// // COMPUTING THE SUN'S POSITION
|
|
// // ----------------------------
|
|
// //
|
|
// // To be able to compute the Sun's rise/set times, you need to be able to
|
|
// // compute the Sun's position at any time. First compute the "day
|
|
// // number" d as outlined above, for the desired moment. Next compute:
|
|
// //
|
|
// double oblecl = 23.4393 - 3.563E-7 * d;
|
|
// //
|
|
// double w = 282.9404 + 4.70935E-5 * d;
|
|
// double M = 356.0470 + 0.9856002585 * d;
|
|
// double e = 0.016709 - 1.151E-9 * d;
|
|
// //
|
|
// // This is the obliquity of the ecliptic, plus some of the elements of
|
|
// // the Sun's apparent orbit (i.e., really the Earth's orbit): w =
|
|
// // argument of perihelion, M = mean anomaly, e = eccentricity.
|
|
// // Semi-major axis is here assumed to be exactly 1.0 (while not strictly
|
|
// // true, this is still an accurate approximation). Next compute E, the
|
|
// // eccentric anomaly:
|
|
// //
|
|
// double E = M + e*(180/PI) * Math.sin(M*DEG_RAD) * ( 1.0 + e*Math.cos(M*DEG_RAD) );
|
|
// //
|
|
// // where E and M are in degrees. This is it---no further iterations are
|
|
// // needed because we know e has a sufficiently small value. Next compute
|
|
// // the true anomaly, v, and the distance, r:
|
|
// //
|
|
// /* r * cos(v) = */ double A = Math.cos(E*DEG_RAD) - e;
|
|
// /* r * sin(v) = */ double B = Math.sqrt(1 - e*e) * Math.sin(E*DEG_RAD);
|
|
// //
|
|
// // and
|
|
// //
|
|
// // r = sqrt( A*A + B*B )
|
|
// double v = Math.atan2( B, A )*RAD_DEG;
|
|
// //
|
|
// // The Sun's true longitude, slon, can now be computed:
|
|
// //
|
|
// double slon = v + w;
|
|
// //
|
|
// // Since the Sun is always at the ecliptic (or at least very very close to
|
|
// // it), we can use simplified formulae to convert slon (the Sun's ecliptic
|
|
// // longitude) to sRA and sDec (the Sun's RA and Dec):
|
|
// //
|
|
// // sin(slon) * cos(oblecl)
|
|
// // tan(sRA) = -------------------------
|
|
// // cos(slon)
|
|
// //
|
|
// // sin(sDec) = sin(oblecl) * sin(slon)
|
|
// //
|
|
// // As was the case when computing az, the Azimuth, if possible use an
|
|
// // atan2() function to compute sRA.
|
|
//
|
|
// double sRA = Math.atan2(Math.sin(slon*DEG_RAD) * Math.cos(oblecl*DEG_RAD), Math.cos(slon*DEG_RAD))*RAD_DEG;
|
|
//
|
|
// double sin_sDec = Math.sin(oblecl*DEG_RAD) * Math.sin(slon*DEG_RAD);
|
|
// double sDec = Math.asin(sin_sDec)*RAD_DEG;
|
|
//
|
|
// // COMPUTING RISE AND SET TIMES
|
|
// // ----------------------------
|
|
// //
|
|
// // To compute when an object rises or sets, you must compute when it
|
|
// // passes the meridian and the HA of rise/set. Then the rise time is
|
|
// // the meridian time minus HA for rise/set, and the set time is the
|
|
// // meridian time plus the HA for rise/set.
|
|
// //
|
|
// // To find the meridian time, compute the Local Sidereal Time at 0h local
|
|
// // time (or 0h UT if you prefer to work in UT) as outlined above---name
|
|
// // that quantity LST0. The Meridian Time, MT, will now be:
|
|
// //
|
|
// // MT = RA - LST0
|
|
// double MT = normalize(sRA - LST, 360);
|
|
// //
|
|
// // where "RA" is the object's Right Ascension (in degrees!). If negative,
|
|
// // add 360 deg to MT. If the object is the Sun, leave the time as it is,
|
|
// // but if it's stellar, multiply MT by 365.2422/366.2422, to convert from
|
|
// // sidereal to solar time. Now, compute HA for rise/set, name that
|
|
// // quantity HA0:
|
|
// //
|
|
// // sin(h0) - sin(lat) * sin(Dec)
|
|
// // cos(HA0) = ---------------------------------
|
|
// // cos(lat) * cos(Dec)
|
|
// //
|
|
// // where h0 is the altitude selected to represent rise/set. For a purely
|
|
// // mathematical horizon, set h0 = 0 and simplify to:
|
|
// //
|
|
// // cos(HA0) = - tan(lat) * tan(Dec)
|
|
// //
|
|
// // If you want to account for refraction on the atmosphere, set h0 = -35/60
|
|
// // degrees (-35 arc minutes), and if you want to compute the rise/set times
|
|
// // for the Sun's upper limb, set h0 = -50/60 (-50 arc minutes).
|
|
// //
|
|
// double h0 = -50/60 * DEG_RAD;
|
|
//
|
|
// double HA0 = Math.acos(
|
|
// (Math.sin(h0) - Math.sin(fLatitude) * sin_sDec) /
|
|
// (Math.cos(fLatitude) * Math.cos(sDec*DEG_RAD)))*RAD_DEG;
|
|
//
|
|
// // When HA0 has been computed, leave it as it is for the Sun but multiply
|
|
// // by 365.2422/366.2422 for stellar objects, to convert from sidereal to
|
|
// // solar time. Finally compute:
|
|
// //
|
|
// // Rise time = MT - HA0
|
|
// // Set time = MT + HA0
|
|
// //
|
|
// // convert the times from degrees to hours by dividing by 15.
|
|
// //
|
|
// // If you'd like to check that your calculations are accurate or just
|
|
// // need a quick result, check the USNO's Sun or Moon Rise/Set Table,
|
|
// // <URL:http://aa.usno.navy.mil/AA/data/docs/RS_OneYear.html>.
|
|
//
|
|
// double result = MT + (rise ? -HA0 : HA0); // in degrees
|
|
//
|
|
// // Find UT midnight on this day
|
|
// long midnight = DAY_MS * (time / DAY_MS);
|
|
//
|
|
// return midnight + (long) (result * 3600000 / 15);
|
|
// }
|
|
|
|
//-------------------------------------------------------------------------
|
|
// The Moon
|
|
//-------------------------------------------------------------------------
|
|
|
|
static const double moonL0; // Mean long. at epoch
|
|
static const double moonP0; // Mean long. of perigee
|
|
static const double moonN0; // Mean long. of node
|
|
static const double moonI; // Inclination of orbit
|
|
static const double moonE; // Eccentricity of orbit
|
|
|
|
// These aren't used right now
|
|
static const double moonA; // semi-major axis (km)
|
|
static const double moonT0; // Angular size at distance A
|
|
static const double moonPi; // Parallax at distance A
|
|
|
|
/**
|
|
* The position of the moon at the time set on this
|
|
* object, in equatorial coordinates.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
Equatorial* getMoonPosition();
|
|
|
|
/**
|
|
* The "age" of the moon at the time specified in this object.
|
|
* This is really the angle between the
|
|
* current ecliptic longitudes of the sun and the moon,
|
|
* measured in radians.
|
|
*
|
|
* @see #getMoonPhase
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getMoonAge();
|
|
|
|
/**
|
|
* Calculate the phase of the moon at the time set in this object.
|
|
* The returned phase is a <code>double</code> in the range
|
|
* <code>0 <= phase < 1</code>, interpreted as follows:
|
|
* <ul>
|
|
* <li>0.00: New moon
|
|
* <li>0.25: First quarter
|
|
* <li>0.50: Full moon
|
|
* <li>0.75: Last quarter
|
|
* </ul>
|
|
*
|
|
* @see #getMoonAge
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
double getMoonPhase();
|
|
|
|
class MoonAge {
|
|
public:
|
|
MoonAge(double l)
|
|
: value(l) { }
|
|
double value;
|
|
};
|
|
|
|
/**
|
|
* Constant representing a new moon.
|
|
* For use with {@link #getMoonTime getMoonTime}
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const MoonAge NEW_MOON;
|
|
|
|
/**
|
|
* Constant representing the moon's first quarter.
|
|
* For use with {@link #getMoonTime getMoonTime}
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const MoonAge FIRST_QUARTER;
|
|
|
|
/**
|
|
* Constant representing a full moon.
|
|
* For use with {@link #getMoonTime getMoonTime}
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const MoonAge FULL_MOON;
|
|
|
|
/**
|
|
* Constant representing the moon's last quarter.
|
|
* For use with {@link #getMoonTime getMoonTime}
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
static const MoonAge LAST_QUARTER;
|
|
|
|
/**
|
|
* Find the next or previous time at which the Moon's ecliptic
|
|
* longitude will have the desired value.
|
|
* <p>
|
|
* @param desired The desired longitude.
|
|
* @param next <tt>true</tt> if the next occurrance of the phase
|
|
* is desired, <tt>false</tt> for the previous occurrance.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate getMoonTime(double desired, UBool next);
|
|
UDate getMoonTime(MoonAge desired, UBool next);
|
|
|
|
/**
|
|
* Returns the time (GMT) of sunrise or sunset on the local date to which
|
|
* this calendar is currently set.
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate getMoonRiseSet(UBool rise);
|
|
|
|
//-------------------------------------------------------------------------
|
|
// Interpolation methods for finding the time at which a given event occurs
|
|
//-------------------------------------------------------------------------
|
|
|
|
// private
|
|
class AngleFunc {
|
|
public:
|
|
virtual double eval(CalendarAstronomer&) = 0;
|
|
};
|
|
friend class AngleFunc;
|
|
|
|
UDate timeOfAngle(AngleFunc& func, double desired,
|
|
double periodDays, double epsilon, UBool next);
|
|
|
|
class CoordFunc {
|
|
public:
|
|
virtual Equatorial* eval(CalendarAstronomer&) = 0;
|
|
};
|
|
friend class CoordFunc;
|
|
|
|
double riseOrSet(CoordFunc& func, UBool rise,
|
|
double diameter, double refraction,
|
|
double epsilon);
|
|
|
|
//-------------------------------------------------------------------------
|
|
// Other utility methods
|
|
//-------------------------------------------------------------------------
|
|
private:
|
|
/***
|
|
* Given 'value', add or subtract 'range' until 0 <= 'value' < range.
|
|
* The modulus operator.
|
|
*/
|
|
inline static double normalize(double value, double range) {
|
|
return value - range * Math::floorDivide(value, range);
|
|
}
|
|
|
|
/**
|
|
* Normalize an angle so that it's in the range 0 - 2pi.
|
|
* For positive angles this is just (angle % 2pi), but the Java
|
|
* mod operator doesn't work that way for negative numbers....
|
|
*/
|
|
inline static double norm2PI(double angle) {
|
|
return normalize(angle, PI2);
|
|
}
|
|
|
|
/**
|
|
* Normalize an angle into the range -PI - PI
|
|
*/
|
|
inline static double normPI(double angle) {
|
|
return normalize(angle + PI, PI2) - PI;
|
|
}
|
|
|
|
/**
|
|
* Find the "true anomaly" (longitude) of an object from
|
|
* its mean anomaly and the eccentricity of its orbit. This uses
|
|
* an iterative solution to Kepler's equation.
|
|
*
|
|
* @param meanAnomaly The object's longitude calculated as if it were in
|
|
* a regular, circular orbit, measured in radians
|
|
* from the point of perigee.
|
|
*
|
|
* @param eccentricity The eccentricity of the orbit
|
|
*
|
|
* @return The true anomaly (longitude) measured in radians
|
|
*/
|
|
double trueAnomaly(double meanAnomaly, double eccentricity);
|
|
|
|
/**
|
|
* Return the obliquity of the ecliptic (the angle between the ecliptic
|
|
* and the earth's equator) at the current time. This varies due to
|
|
* the precession of the earth's axis.
|
|
*
|
|
* @return the obliquity of the ecliptic relative to the equator,
|
|
* measured in radians.
|
|
*/
|
|
double eclipticObliquity();
|
|
|
|
//-------------------------------------------------------------------------
|
|
// Private data
|
|
//-------------------------------------------------------------------------
|
|
private:
|
|
/**
|
|
* Current time in milliseconds since 1/1/1970 AD
|
|
* @see java.util.Date#getTime
|
|
*/
|
|
UDate fTime;
|
|
|
|
/* These aren't used yet, but they'll be needed for sunset calculations
|
|
* and equatorial to horizon coordinate conversions
|
|
*/
|
|
double fLongitude;
|
|
double fLatitude;
|
|
double fGmtOffset;
|
|
|
|
//
|
|
// The following fields are used to cache calculated results for improved
|
|
// performance. These values all depend on the current time setting
|
|
// of this object, so the clearCache method is provided.
|
|
//
|
|
|
|
static const double INVALID;
|
|
|
|
double julianDay ;
|
|
double julianCentury ;
|
|
double sunLongitude ;
|
|
double meanAnomalySun ;
|
|
double moonLongitude ;
|
|
double moonEclipLong ;
|
|
double meanAnomalyMoon ;
|
|
double eclipObliquity ;
|
|
double siderealT0 ;
|
|
double siderealTime ;
|
|
|
|
void clearCache();
|
|
|
|
Equatorial *moonPosition;
|
|
|
|
//private static void out(String s) {
|
|
// System.out.println(s);
|
|
//}
|
|
|
|
//private static String deg(double rad) {
|
|
// return Double.toString(rad * RAD_DEG);
|
|
//}
|
|
|
|
//private static String hours(long ms) {
|
|
// return Double.toString((double)ms / HOUR_MS) + " hours";
|
|
//}
|
|
|
|
/**
|
|
* @internal
|
|
* @deprecated ICU 2.4. This class may be removed or modified.
|
|
*/
|
|
UDate local(UDate localMillis);
|
|
};
|
|
#endif
|
|
#endif
|