| |
| /************************************************************************ |
| * Copyright (C) 1996-2003, International Business Machines Corporation * |
| * and others. All Rights Reserved. * |
| ************************************************************************ |
| * 2003-nov-07 srl Port from Java |
| */ |
| |
| #ifndef ASTRO_H |
| #define ASTRO_H |
| |
| #include "unicode/utypes.h" |
| |
| #if !UCONFIG_NO_FORMATTING |
| |
| #include "gregoimp.h" // for Math |
| #include "stdio.h" // for sprintf |
| #include "unicode/unistr.h" |
| |
| /** |
| * <code>CalendarAstronomer</code> is a class that can perform the calculations to |
| * determine the positions of the sun and moon, the time of sunrise and |
| * sunset, and other astronomy-related data. The calculations it performs |
| * are in some cases quite complicated, and this utility class saves you |
| * the trouble of worrying about them. |
| * <p> |
| * The measurement of time is a very important part of astronomy. Because |
| * astronomical bodies are constantly in motion, observations are only valid |
| * at a given moment in time. Accordingly, each <code>CalendarAstronomer</code> |
| * object has a <code>time</code> property that determines the date |
| * and time for which its calculations are performed. You can set and |
| * retrieve this property with {@link #setDate setDate}, {@link #getDate getDate} |
| * and related methods. |
| * <p> |
| * Almost all of the calculations performed by this class, or by any |
| * astronomer, are approximations to various degrees of accuracy. The |
| * calculations in this class are mostly modelled after those described |
| * in the book |
| * <a href="http://www.amazon.com/exec/obidos/ISBN=0521356997" target="_top"> |
| * Practical Astronomy With Your Calculator</a>, by Peter J. |
| * Duffett-Smith, Cambridge University Press, 1990. This is an excellent |
| * book, and if you want a greater understanding of how these calculations |
| * are performed it a very good, readable starting point. |
| * <p> |
| * <strong>WARNING:</strong> This class is very early in its development, and |
| * it is highly likely that its API will change to some degree in the future. |
| * At the moment, it basically does just enough to support {@link IslamicCalendar} |
| * and {@link ChineseCalendar}. |
| * |
| * @author Laura Werner |
| * @author Alan Liu |
| * @internal |
| */ |
| class U_I18N_API CalendarAstronomer { |
| public: |
| // some classes |
| |
| public: |
| /** |
| * Represents the position of an object in the sky relative to the ecliptic, |
| * the plane of the earth's orbit around the Sun. |
| * This is a spherical coordinate system in which the latitude |
| * specifies the position north or south of the plane of the ecliptic. |
| * The longitude specifies the position along the ecliptic plane |
| * relative to the "First Point of Aries", which is the Sun's position in the sky |
| * at the Vernal Equinox. |
| * <p> |
| * Note that Ecliptic objects are immutable and cannot be modified |
| * once they are constructed. This allows them to be passed and returned by |
| * value without worrying about whether other code will modify them. |
| * |
| * @see CalendarAstronomer.Equatorial |
| * @see CalendarAstronomer.Horizon |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| class U_I18N_API Ecliptic { |
| public: |
| /** |
| * Constructs an Ecliptic coordinate object. |
| * <p> |
| * @param lat The ecliptic latitude, measured in radians. |
| * @param lon The ecliptic longitude, measured in radians. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| Ecliptic(double lat, double lon) { |
| latitude = lat; |
| longitude = lon; |
| } |
| |
| /** |
| * Return a string representation of this object |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| UnicodeString toString() { |
| char tmp[800]; |
| sprintf(tmp, "[%.5f,%.5f]", longitude*RAD_DEG, latitude*RAD_DEG); |
| return UnicodeString(tmp); |
| } |
| |
| /** |
| * The ecliptic latitude, in radians. This specifies an object's |
| * position north or south of the plane of the ecliptic, |
| * with positive angles representing north. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double latitude; |
| |
| /** |
| * The ecliptic longitude, in radians. |
| * This specifies an object's position along the ecliptic plane |
| * relative to the "First Point of Aries", which is the Sun's position |
| * in the sky at the Vernal Equinox, |
| * with positive angles representing east. |
| * <p> |
| * A bit of trivia: the first point of Aries is currently in the |
| * constellation Pisces, due to the precession of the earth's axis. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double longitude; |
| }; |
| |
| /** |
| * Represents the position of an |
| * object in the sky relative to the plane of the earth's equator. |
| * The <i>Right Ascension</i> specifies the position east or west |
| * along the equator, relative to the sun's position at the vernal |
| * equinox. The <i>Declination</i> is the position north or south |
| * of the equatorial plane. |
| * <p> |
| * Note that Equatorial objects are immutable and cannot be modified |
| * once they are constructed. This allows them to be passed and returned by |
| * value without worrying about whether other code will modify them. |
| * |
| * @see CalendarAstronomer.Ecliptic |
| * @see CalendarAstronomer.Horizon |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| class U_I18N_API Equatorial { |
| public: |
| /** |
| * Constructs an Equatorial coordinate object. |
| * <p> |
| * @param asc The right ascension, measured in radians. |
| * @param dec The declination, measured in radians. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| Equatorial(double asc, double dec) |
| : ascension(asc), declination(dec) { } |
| |
| /** |
| * Return a string representation of this object, with the |
| * angles measured in degrees. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| UnicodeString toString() const { |
| char tmp[400]; |
| sprintf(tmp, "%f,%f", |
| (ascension*RAD_DEG), (declination*RAD_DEG)); |
| return UnicodeString(tmp); |
| } |
| |
| /** |
| * Return a string representation of this object with the right ascension |
| * measured in hours, minutes, and seconds. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| //String toHmsString() { |
| //return radToHms(ascension) + "," + radToDms(declination); |
| //} |
| |
| /** |
| * The right ascension, in radians. |
| * This is the position east or west along the equator |
| * relative to the sun's position at the vernal equinox, |
| * with positive angles representing East. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double ascension; |
| |
| /** |
| * The declination, in radians. |
| * This is the position north or south of the equatorial plane, |
| * with positive angles representing north. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double declination; |
| }; |
| |
| /** |
| * Represents the position of an object in the sky relative to |
| * the local horizon. |
| * The <i>Altitude</i> represents the object's elevation above the horizon, |
| * with objects below the horizon having a negative altitude. |
| * The <i>Azimuth</i> is the geographic direction of the object from the |
| * observer's position, with 0 representing north. The azimuth increases |
| * clockwise from north. |
| * <p> |
| * Note that Horizon objects are immutable and cannot be modified |
| * once they are constructed. This allows them to be passed and returned by |
| * value without worrying about whether other code will modify them. |
| * |
| * @see CalendarAstronomer.Ecliptic |
| * @see CalendarAstronomer.Equatorial |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| class U_I18N_API Horizon { |
| public: |
| /** |
| * Constructs a Horizon coordinate object. |
| * <p> |
| * @param alt The altitude, measured in radians above the horizon. |
| * @param azim The azimuth, measured in radians clockwise from north. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| Horizon(double alt, double azim) |
| : altitude(alt), azimuth(azim) { } |
| |
| /** |
| * Return a string representation of this object, with the |
| * angles measured in degrees. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| UnicodeString toString() { |
| char tmp[800]; |
| sprintf(tmp, "[%.5f,%.5f]", altitude*RAD_DEG, azimuth*RAD_DEG); |
| return UnicodeString(tmp); |
| } |
| |
| /** |
| * The object's altitude above the horizon, in radians. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| const double altitude; |
| |
| /** |
| * The object's direction, in radians clockwise from north. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| const double azimuth; |
| }; |
| |
| public: |
| //------------------------------------------------------------------------- |
| // Astronomical constants |
| //------------------------------------------------------------------------- |
| /** |
| * The number of standard hours in one sidereal day. |
| * Approximately 24.93. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double SIDEREAL_DAY; |
| |
| /** |
| * The number of sidereal hours in one mean solar day. |
| * Approximately 24.07. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double SOLAR_DAY; |
| |
| /** |
| * The average number of solar days from one new moon to the next. This is the time |
| * it takes for the moon to return the same ecliptic longitude as the sun. |
| * It is longer than the sidereal month because the sun's longitude increases |
| * during the year due to the revolution of the earth around the sun. |
| * Approximately 29.53. |
| * |
| * @see #SIDEREAL_MONTH |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double SYNODIC_MONTH; |
| |
| /** |
| * The average number of days it takes |
| * for the moon to return to the same ecliptic longitude relative to the |
| * stellar background. This is referred to as the sidereal month. |
| * It is shorter than the synodic month due to |
| * the revolution of the earth around the sun. |
| * Approximately 27.32. |
| * |
| * @see #SYNODIC_MONTH |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double SIDEREAL_MONTH; |
| |
| /** |
| * The average number number of days between successive vernal equinoxes. |
| * Due to the precession of the earth's |
| * axis, this is not precisely the same as the sidereal year. |
| * Approximately 365.24 |
| * |
| * @see #SIDEREAL_YEAR |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double TROPICAL_YEAR; |
| |
| /** |
| * The average number of days it takes |
| * for the sun to return to the same position against the fixed stellar |
| * background. This is the duration of one orbit of the earth about the sun |
| * as it would appear to an outside observer. |
| * Due to the precession of the earth's |
| * axis, this is not precisely the same as the tropical year. |
| * Approximately 365.25. |
| * |
| * @see #TROPICAL_YEAR |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double SIDEREAL_YEAR; |
| |
| //------------------------------------------------------------------------- |
| // Time-related constants |
| //------------------------------------------------------------------------- |
| |
| /** |
| * The number of milliseconds in one second. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const int32_t SECOND_MS; |
| |
| /** |
| * The number of milliseconds in one minute. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const int32_t MINUTE_MS; |
| |
| /** |
| * The number of milliseconds in one hour. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const int32_t HOUR_MS; |
| |
| /** |
| * The number of milliseconds in one day. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double DAY_MS; |
| |
| /** |
| * The start of the julian day numbering scheme used by astronomers, which |
| * is 1/1/4713 BC (Julian), 12:00 GMT. This is given as the number of milliseconds |
| * since 1/1/1970 AD (Gregorian), a negative number. |
| * Note that julian day numbers and |
| * the Julian calendar are <em>not</em> the same thing. Also note that |
| * julian days start at <em>noon</em>, not midnight. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| static const double JULIAN_EPOCH_MS; |
| |
| // static { |
| // Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT")); |
| // cal.clear(); |
| // cal.set(cal.ERA, 0); |
| // cal.set(cal.YEAR, 4713); |
| // cal.set(cal.MONTH, cal.JANUARY); |
| // cal.set(cal.DATE, 1); |
| // cal.set(cal.HOUR_OF_DAY, 12); |
| // System.out.println("1.5 Jan 4713 BC = " + cal.getTime().getTime()); |
| |
| // cal.clear(); |
| // cal.set(cal.YEAR, 2000); |
| // cal.set(cal.MONTH, cal.JANUARY); |
| // cal.set(cal.DATE, 1); |
| // cal.add(cal.DATE, -1); |
| // System.out.println("0.0 Jan 2000 = " + cal.getTime().getTime()); |
| // } |
| |
| /** |
| * Milliseconds value for 0.0 January 2000 AD. |
| */ |
| static const double EPOCH_2000_MS; |
| |
| //------------------------------------------------------------------------- |
| // Assorted private data used for conversions |
| //------------------------------------------------------------------------- |
| |
| // My own copies of these so compilers are more likely to optimize them away |
| static const double PI; |
| static const double PI2; |
| |
| static const double RAD_HOUR; |
| static const double DEG_RAD; |
| static const double RAD_DEG; |
| |
| //------------------------------------------------------------------------- |
| // Constructors |
| //------------------------------------------------------------------------- |
| |
| /** |
| * Construct a new <code>CalendarAstronomer</code> object that is initialized to |
| * the current date and time. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| CalendarAstronomer(); |
| |
| /** |
| * Construct a new <code>CalendarAstronomer</code> object that is initialized to |
| * the specified date and time. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| CalendarAstronomer(UDate d); |
| |
| |
| /** |
| * Construct a new <code>CalendarAstronomer</code> object with the given |
| * latitude and longitude. The object's time is set to the current |
| * date and time. |
| * <p> |
| * @param longitude The desired longitude, in <em>degrees</em> east of |
| * the Greenwich meridian. |
| * |
| * @param latitude The desired latitude, in <em>degrees</em>. Positive |
| * values signify North, negative South. |
| * |
| * @see java.util.Date#getTime() |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| CalendarAstronomer(double longitude, double latitude); |
| |
| ~CalendarAstronomer(); |
| |
| |
| //------------------------------------------------------------------------- |
| // Time and date getters and setters |
| //------------------------------------------------------------------------- |
| |
| /** |
| * Set the current date and time of this <code>CalendarAstronomer</code> object. All |
| * astronomical calculations are performed based on this time setting. |
| * |
| * @param aTime the date and time, expressed as the number of milliseconds since |
| * 1/1/1970 0:00 GMT (Gregorian). |
| * |
| * @see #setDate |
| * @see #getTime |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| void setTime(UDate aTime); |
| |
| |
| /** |
| * Set the current date and time of this <code>CalendarAstronomer</code> object. All |
| * astronomical calculations are performed based on this time setting. |
| * |
| * @param aTime the date and time, expressed as the number of milliseconds since |
| * 1/1/1970 0:00 GMT (Gregorian). |
| * |
| * @see #getTime |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| void setDate(UDate aDate) { setTime(aDate); } |
| |
| /** |
| * Set the current date and time of this <code>CalendarAstronomer</code> object. All |
| * astronomical calculations are performed based on this time setting. |
| * |
| * @param jdn the desired time, expressed as a "julian day number", |
| * which is the number of elapsed days since |
| * 1/1/4713 BC (Julian), 12:00 GMT. Note that julian day |
| * numbers start at <em>noon</em>. To get the jdn for |
| * the corresponding midnight, subtract 0.5. |
| * |
| * @see #getJulianDay |
| * @see #JULIAN_EPOCH_MS |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| void setJulianDay(double jdn); |
| |
| /** |
| * Get the current time of this <code>CalendarAstronomer</code> object, |
| * represented as the number of milliseconds since |
| * 1/1/1970 AD 0:00 GMT (Gregorian). |
| * |
| * @see #setTime |
| * @see #getDate |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| UDate getTime(); |
| |
| /** |
| * Get the current time of this <code>CalendarAstronomer</code> object, |
| * expressed as a "julian day number", which is the number of elapsed |
| * days since 1/1/4713 BC (Julian), 12:00 GMT. |
| * |
| * @see #setJulianDay |
| * @see #JULIAN_EPOCH_MS |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double getJulianDay(); |
| |
| /** |
| * 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 U_I18N_API 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 U_I18N_API 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 U_I18N_API AngleFunc { |
| public: |
| virtual double eval(CalendarAstronomer&) = 0; |
| }; |
| friend class AngleFunc; |
| |
| UDate timeOfAngle(AngleFunc& func, double desired, |
| double periodDays, double epsilon, UBool next); |
| |
| class U_I18N_API 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 |
