| /************************************************************************ |
| * Copyright (C) 1996-2012, International Business Machines Corporation |
| * and others. All Rights Reserved. |
| ************************************************************************ |
| * 2003-nov-07 srl Port from Java |
| */ |
| |
| #include "astro.h" |
| |
| #if !UCONFIG_NO_FORMATTING |
| |
| #include "unicode/calendar.h" |
| #include <math.h> |
| #include <float.h> |
| #include "unicode/putil.h" |
| #include "uhash.h" |
| #include "umutex.h" |
| #include "ucln_in.h" |
| #include "putilimp.h" |
| #include <stdio.h> // for toString() |
| |
| #if defined (PI) |
| #undef PI |
| #endif |
| |
| #ifdef U_DEBUG_ASTRO |
| # include "uresimp.h" // for debugging |
| |
| static void debug_astro_loc(const char *f, int32_t l) |
| { |
| fprintf(stderr, "%s:%d: ", f, l); |
| } |
| |
| static void debug_astro_msg(const char *pat, ...) |
| { |
| va_list ap; |
| va_start(ap, pat); |
| vfprintf(stderr, pat, ap); |
| fflush(stderr); |
| } |
| #include "unicode/datefmt.h" |
| #include "unicode/ustring.h" |
| static const char * debug_astro_date(UDate d) { |
| static char gStrBuf[1024]; |
| static DateFormat *df = NULL; |
| if(df == NULL) { |
| df = DateFormat::createDateTimeInstance(DateFormat::MEDIUM, DateFormat::MEDIUM, Locale::getUS()); |
| df->adoptTimeZone(TimeZone::getGMT()->clone()); |
| } |
| UnicodeString str; |
| df->format(d,str); |
| u_austrncpy(gStrBuf,str.getTerminatedBuffer(),sizeof(gStrBuf)-1); |
| return gStrBuf; |
| } |
| |
| // must use double parens, i.e.: U_DEBUG_ASTRO_MSG(("four is: %d",4)); |
| #define U_DEBUG_ASTRO_MSG(x) {debug_astro_loc(__FILE__,__LINE__);debug_astro_msg x;} |
| #else |
| #define U_DEBUG_ASTRO_MSG(x) |
| #endif |
| |
| static inline UBool isINVALID(double d) { |
| return(uprv_isNaN(d)); |
| } |
| |
| static UMutex ccLock = U_MUTEX_INITIALIZER; |
| |
| U_CDECL_BEGIN |
| static UBool calendar_astro_cleanup(void) { |
| return TRUE; |
| } |
| U_CDECL_END |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * The number of standard hours in one sidereal day. |
| * Approximately 24.93. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| #define SIDEREAL_DAY (23.93446960027) |
| |
| /** |
| * 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. |
| */ |
| #define SOLAR_DAY (24.065709816) |
| |
| /** |
| * 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. |
| */ |
| const double CalendarAstronomer::SYNODIC_MONTH = 29.530588853; |
| |
| /** |
| * 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. |
| */ |
| #define SIDEREAL_MONTH 27.32166 |
| |
| /** |
| * 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. |
| */ |
| #define TROPICAL_YEAR 365.242191 |
| |
| /** |
| * 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. |
| */ |
| #define SIDEREAL_YEAR 365.25636 |
| |
| //------------------------------------------------------------------------- |
| // Time-related constants |
| //------------------------------------------------------------------------- |
| |
| /** |
| * The number of milliseconds in one second. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| #define SECOND_MS U_MILLIS_PER_SECOND |
| |
| /** |
| * The number of milliseconds in one minute. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| #define MINUTE_MS U_MILLIS_PER_MINUTE |
| |
| /** |
| * The number of milliseconds in one hour. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| #define HOUR_MS U_MILLIS_PER_HOUR |
| |
| /** |
| * The number of milliseconds in one day. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| #define DAY_MS U_MILLIS_PER_DAY |
| |
| /** |
| * 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. |
| */ |
| #define JULIAN_EPOCH_MS -210866760000000.0 |
| |
| |
| /** |
| * Milliseconds value for 0.0 January 2000 AD. |
| */ |
| #define EPOCH_2000_MS 946598400000.0 |
| |
| //------------------------------------------------------------------------- |
| // Assorted private data used for conversions |
| //------------------------------------------------------------------------- |
| |
| // My own copies of these so compilers are more likely to optimize them away |
| const double CalendarAstronomer::PI = 3.14159265358979323846; |
| |
| #define CalendarAstronomer_PI2 (CalendarAstronomer::PI*2.0) |
| #define RAD_HOUR ( 12 / CalendarAstronomer::PI ) // radians -> hours |
| #define DEG_RAD ( CalendarAstronomer::PI / 180 ) // degrees -> radians |
| #define RAD_DEG ( 180 / CalendarAstronomer::PI ) // radians -> degrees |
| |
| /*** |
| * Given 'value', add or subtract 'range' until 0 <= 'value' < range. |
| * The modulus operator. |
| */ |
| inline static double normalize(double value, double range) { |
| return value - range * ClockMath::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, CalendarAstronomer::PI * 2.0); |
| } |
| |
| /** |
| * Normalize an angle into the range -PI - PI |
| */ |
| inline static double normPI(double angle) { |
| return normalize(angle + CalendarAstronomer::PI, CalendarAstronomer::PI * 2.0) - CalendarAstronomer::PI; |
| } |
| |
| //------------------------------------------------------------------------- |
| // 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::CalendarAstronomer(): |
| fTime(Calendar::getNow()), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(FALSE) { |
| clearCache(); |
| } |
| |
| /** |
| * 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::CalendarAstronomer(UDate d): fTime(d), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(FALSE) { |
| clearCache(); |
| } |
| |
| /** |
| * 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::CalendarAstronomer(double longitude, double latitude) : |
| fTime(Calendar::getNow()), moonPosition(0,0), moonPositionSet(FALSE) { |
| fLongitude = normPI(longitude * (double)DEG_RAD); |
| fLatitude = normPI(latitude * (double)DEG_RAD); |
| fGmtOffset = (double)(fLongitude * 24. * (double)HOUR_MS / (double)CalendarAstronomer_PI2); |
| clearCache(); |
| } |
| |
| CalendarAstronomer::~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 CalendarAstronomer::setTime(UDate aTime) { |
| fTime = aTime; |
| U_DEBUG_ASTRO_MSG(("setTime(%.1lf, %sL)\n", aTime, debug_astro_date(aTime+fGmtOffset))); |
| clearCache(); |
| } |
| |
| /** |
| * 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 CalendarAstronomer::setJulianDay(double jdn) { |
| fTime = (double)(jdn * DAY_MS) + JULIAN_EPOCH_MS; |
| clearCache(); |
| julianDay = 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 CalendarAstronomer::getTime() { |
| return fTime; |
| } |
| |
| /** |
| * 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 CalendarAstronomer::getJulianDay() { |
| if (isINVALID(julianDay)) { |
| julianDay = (fTime - (double)JULIAN_EPOCH_MS) / (double)DAY_MS; |
| } |
| return julianDay; |
| } |
| |
| /** |
| * 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 CalendarAstronomer::getJulianCentury() { |
| if (isINVALID(julianCentury)) { |
| julianCentury = (getJulianDay() - 2415020.0) / 36525.0; |
| } |
| return julianCentury; |
| } |
| |
| /** |
| * Returns the current Greenwich sidereal time, measured in hours |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double CalendarAstronomer::getGreenwichSidereal() { |
| if (isINVALID(siderealTime)) { |
| // See page 86 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| |
| double UT = normalize(fTime/(double)HOUR_MS, 24.); |
| |
| siderealTime = normalize(getSiderealOffset() + UT*1.002737909, 24.); |
| } |
| return siderealTime; |
| } |
| |
| double CalendarAstronomer::getSiderealOffset() { |
| if (isINVALID(siderealT0)) { |
| double JD = uprv_floor(getJulianDay() - 0.5) + 0.5; |
| double S = JD - 2451545.0; |
| double T = S / 36525.0; |
| siderealT0 = normalize(6.697374558 + 2400.051336*T + 0.000025862*T*T, 24); |
| } |
| return siderealT0; |
| } |
| |
| /** |
| * Returns the current local sidereal time, measured in hours |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| double CalendarAstronomer::getLocalSidereal() { |
| return normalize(getGreenwichSidereal() + (fGmtOffset/(double)HOUR_MS), 24.); |
| } |
| |
| /** |
| * 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. |
| */ |
| double CalendarAstronomer::lstToUT(double lst) { |
| // Convert to local mean time |
| double lt = normalize((lst - getSiderealOffset()) * 0.9972695663, 24); |
| |
| // Then find local midnight on this day |
| double base = (DAY_MS * ClockMath::floorDivide(fTime + fGmtOffset,(double)DAY_MS)) - fGmtOffset; |
| |
| //out(" lt =" + lt + " hours"); |
| //out(" base=" + new Date(base)); |
| |
| return base + (long)(lt * HOUR_MS); |
| } |
| |
| |
| //------------------------------------------------------------------------- |
| // Coordinate transformations, all based on the current time of this object |
| //------------------------------------------------------------------------- |
| |
| /** |
| * Convert from ecliptic to equatorial coordinates. |
| * |
| * @param ecliptic A point in the sky in ecliptic coordinates. |
| * @return The corresponding point in equatorial coordinates. |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, const CalendarAstronomer::Ecliptic& ecliptic) |
| { |
| return eclipticToEquatorial(result, ecliptic.longitude, ecliptic.latitude); |
| } |
| |
| /** |
| * 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. |
| */ |
| CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong, double eclipLat) |
| { |
| // See page 42 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| |
| double obliq = eclipticObliquity(); |
| double sinE = ::sin(obliq); |
| double cosE = cos(obliq); |
| |
| double sinL = ::sin(eclipLong); |
| double cosL = cos(eclipLong); |
| |
| double sinB = ::sin(eclipLat); |
| double cosB = cos(eclipLat); |
| double tanB = tan(eclipLat); |
| |
| result.set(atan2(sinL*cosE - tanB*sinE, cosL), |
| asin(sinB*cosE + cosB*sinE*sinL) ); |
| return result; |
| } |
| |
| /** |
| * 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. |
| */ |
| CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong) |
| { |
| return eclipticToEquatorial(result, eclipLong, 0); // TODO: optimize |
| } |
| |
| /** |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| CalendarAstronomer::Horizon& CalendarAstronomer::eclipticToHorizon(CalendarAstronomer::Horizon& result, double eclipLong) |
| { |
| Equatorial equatorial; |
| eclipticToEquatorial(equatorial, eclipLong); |
| |
| double H = getLocalSidereal()*CalendarAstronomer::PI/12 - equatorial.ascension; // Hour-angle |
| |
| double sinH = ::sin(H); |
| double cosH = cos(H); |
| double sinD = ::sin(equatorial.declination); |
| double cosD = cos(equatorial.declination); |
| double sinL = ::sin(fLatitude); |
| double cosL = cos(fLatitude); |
| |
| double altitude = asin(sinD*sinL + cosD*cosL*cosH); |
| double azimuth = atan2(-cosD*cosL*sinH, sinD - sinL * ::sin(altitude)); |
| |
| result.set(azimuth, altitude); |
| return result; |
| } |
| |
| |
| //------------------------------------------------------------------------- |
| // The Sun |
| //------------------------------------------------------------------------- |
| |
| // |
| // Parameters of the Sun's orbit as of the epoch Jan 0.0 1990 |
| // Angles are in radians (after multiplying by CalendarAstronomer::PI/180) |
| // |
| #define JD_EPOCH 2447891.5 // Julian day of epoch |
| |
| #define SUN_ETA_G (279.403303 * CalendarAstronomer::PI/180) // Ecliptic longitude at epoch |
| #define SUN_OMEGA_G (282.768422 * CalendarAstronomer::PI/180) // Ecliptic longitude of perigee |
| #define SUN_E 0.016713 // Eccentricity of orbit |
| //double sunR0 1.495585e8 // Semi-major axis in KM |
| //double sunTheta0 (0.533128 * CalendarAstronomer::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; |
| // } |
| |
| /** |
| * 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 |
| */ |
| static double trueAnomaly(double meanAnomaly, double eccentricity) |
| { |
| // First, solve Kepler's equation iteratively |
| // Duffett-Smith, p.90 |
| double delta; |
| double E = meanAnomaly; |
| do { |
| delta = E - eccentricity * ::sin(E) - meanAnomaly; |
| E = E - delta / (1 - eccentricity * ::cos(E)); |
| } |
| while (uprv_fabs(delta) > 1e-5); // epsilon = 1e-5 rad |
| |
| return 2.0 * ::atan( ::tan(E/2) * ::sqrt( (1+eccentricity) |
| /(1-eccentricity) ) ); |
| } |
| |
| /** |
| * 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 CalendarAstronomer::getSunLongitude() |
| { |
| // See page 86 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| |
| if (isINVALID(sunLongitude)) { |
| getSunLongitude(getJulianDay(), sunLongitude, meanAnomalySun); |
| } |
| return sunLongitude; |
| } |
| |
| /** |
| * TODO Make this public when the entire class is package-private. |
| */ |
| /*public*/ void CalendarAstronomer::getSunLongitude(double jDay, double &longitude, double &meanAnomaly) |
| { |
| // See page 86 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| |
| double day = jDay - JD_EPOCH; // Days since epoch |
| |
| // Find the angular distance the sun in a fictitious |
| // circular orbit has travelled since the epoch. |
| double epochAngle = norm2PI(CalendarAstronomer_PI2/TROPICAL_YEAR*day); |
| |
| // The epoch wasn't at the sun's perigee; find the angular distance |
| // since perigee, which is called the "mean anomaly" |
| meanAnomaly = norm2PI(epochAngle + SUN_ETA_G - SUN_OMEGA_G); |
| |
| // Now find the "true anomaly", e.g. the real solar longitude |
| // by solving Kepler's equation for an elliptical orbit |
| // NOTE: The 3rd ed. of the book lists omega_g and eta_g in different |
| // equations; omega_g is to be correct. |
| longitude = norm2PI(trueAnomaly(meanAnomaly, SUN_E) + SUN_OMEGA_G); |
| } |
| |
| /** |
| * 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. |
| */ |
| CalendarAstronomer::Equatorial& CalendarAstronomer::getSunPosition(CalendarAstronomer::Equatorial& result) { |
| return eclipticToEquatorial(result, getSunLongitude(), 0); |
| } |
| |
| |
| /** |
| * 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. |
| */ |
| /*double CalendarAstronomer::VERNAL_EQUINOX() { |
| return 0; |
| }*/ |
| |
| /** |
| * 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. |
| */ |
| double CalendarAstronomer::SUMMER_SOLSTICE() { |
| return (CalendarAstronomer::PI/2); |
| } |
| |
| /** |
| * 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. |
| */ |
| /*double CalendarAstronomer::AUTUMN_EQUINOX() { |
| return (CalendarAstronomer::PI); |
| }*/ |
| |
| /** |
| * 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. |
| */ |
| double CalendarAstronomer::WINTER_SOLSTICE() { |
| return ((CalendarAstronomer::PI*3)/2); |
| } |
| |
| CalendarAstronomer::AngleFunc::~AngleFunc() {} |
| |
| /** |
| * 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. |
| */ |
| class SunTimeAngleFunc : public CalendarAstronomer::AngleFunc { |
| public: |
| virtual ~SunTimeAngleFunc(); |
| virtual double eval(CalendarAstronomer& a) { return a.getSunLongitude(); } |
| }; |
| |
| SunTimeAngleFunc::~SunTimeAngleFunc() {} |
| |
| UDate CalendarAstronomer::getSunTime(double desired, UBool next) |
| { |
| SunTimeAngleFunc func; |
| return timeOfAngle( func, |
| desired, |
| TROPICAL_YEAR, |
| MINUTE_MS, |
| next); |
| } |
| |
| CalendarAstronomer::CoordFunc::~CoordFunc() {} |
| |
| class RiseSetCoordFunc : public CalendarAstronomer::CoordFunc { |
| public: |
| virtual ~RiseSetCoordFunc(); |
| virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { a.getSunPosition(result); } |
| }; |
| |
| RiseSetCoordFunc::~RiseSetCoordFunc() {} |
| |
| UDate CalendarAstronomer::getSunRiseSet(UBool rise) |
| { |
| UDate t0 = fTime; |
| |
| // Make a rough guess: 6am or 6pm local time on the current day |
| double noon = ClockMath::floorDivide(fTime + fGmtOffset, (double)DAY_MS)*DAY_MS - fGmtOffset + (12*HOUR_MS); |
| |
| U_DEBUG_ASTRO_MSG(("Noon=%.2lf, %sL, gmtoff %.2lf\n", noon, debug_astro_date(noon+fGmtOffset), fGmtOffset)); |
| setTime(noon + ((rise ? -6 : 6) * HOUR_MS)); |
| U_DEBUG_ASTRO_MSG(("added %.2lf ms as a guess,\n", ((rise ? -6. : 6.) * HOUR_MS))); |
| |
| RiseSetCoordFunc func; |
| double t = riseOrSet(func, |
| rise, |
| .533 * DEG_RAD, // Angular Diameter |
| 34. /60.0 * DEG_RAD, // Refraction correction |
| MINUTE_MS / 12.); // Desired accuracy |
| |
| setTime(t0); |
| return t; |
| } |
| |
| // 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 when the entire class is package-private. |
| // */ |
| // /*public*/ long getSunRiseSet2(boolean rise) { |
| // // 1. Calculate coordinates of the sun's center for midnight |
| // double jd = uprv_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 = ::tan(fLatitude); |
| // double H = ::acos(-tanL * ::tan(pos1.declination)); |
| // double lst1r = (CalendarAstronomer_PI2 + pos1.ascension - H) * 24 / CalendarAstronomer_PI2; |
| // double lst1s = (pos1.ascension + H) * 24 / CalendarAstronomer_PI2; |
| // H = ::acos(-tanL * ::tan(pos2.declination)); |
| // double lst2r = (CalendarAstronomer_PI2-H + pos2.ascension ) * 24 / CalendarAstronomer_PI2; |
| // double lst2s = (H + pos2.ascension ) * 24 / CalendarAstronomer_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 = ::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 = ::acos(sin(fLatitude) / cos(dec)); |
| // double x = 0.830725 * DEG_RAD; // parallax+refraction+diameter |
| // double y = ::asin(sin(x) / ::sin(psi)) * RAD_DEG; |
| // double delta_t = 240 * y / 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 / CalendarAstronomer_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 = uprv_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 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) * ::sin(M*DEG_RAD) * ( 1.0 + e*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 = cos(E*DEG_RAD) - e; |
| // /* r * ::sin(v) = */ double B = ::sqrt(1 - e*e) * ::sin(E*DEG_RAD); |
| // // |
| // // and |
| // // |
| // // r = sqrt( A*A + B*B ) |
| // double v = ::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 = ::atan2(sin(slon*DEG_RAD) * cos(oblecl*DEG_RAD), cos(slon*DEG_RAD))*RAD_DEG; |
| // |
| // double sin_sDec = ::sin(oblecl*DEG_RAD) * ::sin(slon*DEG_RAD); |
| // double sDec = ::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 = ::acos( |
| // (sin(h0) - ::sin(fLatitude) * sin_sDec) / |
| // (cos(fLatitude) * 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 |
| //------------------------------------------------------------------------- |
| |
| #define moonL0 (318.351648 * CalendarAstronomer::PI/180 ) // Mean long. at epoch |
| #define moonP0 ( 36.340410 * CalendarAstronomer::PI/180 ) // Mean long. of perigee |
| #define moonN0 ( 318.510107 * CalendarAstronomer::PI/180 ) // Mean long. of node |
| #define moonI ( 5.145366 * CalendarAstronomer::PI/180 ) // Inclination of orbit |
| #define moonE ( 0.054900 ) // Eccentricity of orbit |
| |
| // These aren't used right now |
| #define moonA ( 3.84401e5 ) // semi-major axis (km) |
| #define moonT0 ( 0.5181 * CalendarAstronomer::PI/180 ) // Angular size at distance A |
| #define moonPi ( 0.9507 * CalendarAstronomer::PI/180 ) // 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. |
| */ |
| const CalendarAstronomer::Equatorial& CalendarAstronomer::getMoonPosition() |
| { |
| // |
| // See page 142 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| // |
| if (moonPositionSet == FALSE) { |
| // Calculate the solar longitude. Has the side effect of |
| // filling in "meanAnomalySun" as well. |
| getSunLongitude(); |
| |
| // |
| // Find the # of days since the epoch of our orbital parameters. |
| // TODO: Convert the time of day portion into ephemeris time |
| // |
| double day = getJulianDay() - JD_EPOCH; // Days since epoch |
| |
| // Calculate the mean longitude and anomaly of the moon, based on |
| // a circular orbit. Similar to the corresponding solar calculation. |
| double meanLongitude = norm2PI(13.1763966*PI/180*day + moonL0); |
| meanAnomalyMoon = norm2PI(meanLongitude - 0.1114041*PI/180 * day - moonP0); |
| |
| // |
| // Calculate the following corrections: |
| // Evection: the sun's gravity affects the moon's eccentricity |
| // Annual Eqn: variation in the effect due to earth-sun distance |
| // A3: correction factor (for ???) |
| // |
| double evection = 1.2739*PI/180 * ::sin(2 * (meanLongitude - sunLongitude) |
| - meanAnomalyMoon); |
| double annual = 0.1858*PI/180 * ::sin(meanAnomalySun); |
| double a3 = 0.3700*PI/180 * ::sin(meanAnomalySun); |
| |
| meanAnomalyMoon += evection - annual - a3; |
| |
| // |
| // More correction factors: |
| // center equation of the center correction |
| // a4 yet another error correction (???) |
| // |
| // TODO: Skip the equation of the center correction and solve Kepler's eqn? |
| // |
| double center = 6.2886*PI/180 * ::sin(meanAnomalyMoon); |
| double a4 = 0.2140*PI/180 * ::sin(2 * meanAnomalyMoon); |
| |
| // Now find the moon's corrected longitude |
| moonLongitude = meanLongitude + evection + center - annual + a4; |
| |
| // |
| // And finally, find the variation, caused by the fact that the sun's |
| // gravitational pull on the moon varies depending on which side of |
| // the earth the moon is on |
| // |
| double variation = 0.6583*CalendarAstronomer::PI/180 * ::sin(2*(moonLongitude - sunLongitude)); |
| |
| moonLongitude += variation; |
| |
| // |
| // What we've calculated so far is the moon's longitude in the plane |
| // of its own orbit. Now map to the ecliptic to get the latitude |
| // and longitude. First we need to find the longitude of the ascending |
| // node, the position on the ecliptic where it is crossed by the moon's |
| // orbit as it crosses from the southern to the northern hemisphere. |
| // |
| double nodeLongitude = norm2PI(moonN0 - 0.0529539*PI/180 * day); |
| |
| nodeLongitude -= 0.16*PI/180 * ::sin(meanAnomalySun); |
| |
| double y = ::sin(moonLongitude - nodeLongitude); |
| double x = cos(moonLongitude - nodeLongitude); |
| |
| moonEclipLong = ::atan2(y*cos(moonI), x) + nodeLongitude; |
| double moonEclipLat = ::asin(y * ::sin(moonI)); |
| |
| eclipticToEquatorial(moonPosition, moonEclipLong, moonEclipLat); |
| moonPositionSet = TRUE; |
| } |
| return moonPosition; |
| } |
| |
| /** |
| * 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 CalendarAstronomer::getMoonAge() { |
| // See page 147 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| // |
| // Force the moon's position to be calculated. We're going to use |
| // some the intermediate results cached during that calculation. |
| // |
| getMoonPosition(); |
| |
| return norm2PI(moonEclipLong - sunLongitude); |
| } |
| |
| /** |
| * 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 CalendarAstronomer::getMoonPhase() { |
| // See page 147 of "Practial Astronomy with your Calculator", |
| // by Peter Duffet-Smith, for details on the algorithm. |
| return 0.5 * (1 - cos(getMoonAge())); |
| } |
| |
| /** |
| * Constant representing a new moon. |
| * For use with {@link #getMoonTime getMoonTime} |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| const CalendarAstronomer::MoonAge CalendarAstronomer::NEW_MOON() { |
| return CalendarAstronomer::MoonAge(0); |
| } |
| |
| /** |
| * 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. |
| */ |
| /*const CalendarAstronomer::MoonAge CalendarAstronomer::FIRST_QUARTER() { |
| return CalendarAstronomer::MoonAge(CalendarAstronomer::PI/2); |
| }*/ |
| |
| /** |
| * Constant representing a full moon. |
| * For use with {@link #getMoonTime getMoonTime} |
| * @internal |
| * @deprecated ICU 2.4. This class may be removed or modified. |
| */ |
| const CalendarAstronomer::MoonAge CalendarAstronomer::FULL_MOON() { |
| return CalendarAstronomer::MoonAge(CalendarAstronomer::PI); |
| } |
| /** |
| * 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. |
| */ |
| |
| class MoonTimeAngleFunc : public CalendarAstronomer::AngleFunc { |
| public: |
| virtual ~MoonTimeAngleFunc(); |
| virtual double eval(CalendarAstronomer&a) { return a.getMoonAge(); } |
| }; |
| |
| MoonTimeAngleFunc::~MoonTimeAngleFunc() {} |
| |
| /*const CalendarAstronomer::MoonAge CalendarAstronomer::LAST_QUARTER() { |
| return CalendarAstronomer::MoonAge((CalendarAstronomer::PI*3)/2); |
| }*/ |
| |
| /** |
| * 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 CalendarAstronomer::getMoonTime(double desired, UBool next) |
| { |
| MoonTimeAngleFunc func; |
| return timeOfAngle( func, |
| desired, |
| SYNODIC_MONTH, |
| MINUTE_MS, |
| next); |
| } |
| |
| /** |
| * Find the next or previous time at which the moon will be in the |
| * desired phase. |
| * <p> |
| * @param desired The desired phase of the moon. |
| * @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 CalendarAstronomer::getMoonTime(const CalendarAstronomer::MoonAge& desired, UBool next) { |
| return getMoonTime(desired.value, next); |
| } |
| |
| class MoonRiseSetCoordFunc : public CalendarAstronomer::CoordFunc { |
| public: |
| virtual ~MoonRiseSetCoordFunc(); |
| virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { result = a.getMoonPosition(); } |
| }; |
| |
| MoonRiseSetCoordFunc::~MoonRiseSetCoordFunc() {} |
| |
| /** |
| * 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 CalendarAstronomer::getMoonRiseSet(UBool rise) |
| { |
| MoonRiseSetCoordFunc func; |
| return riseOrSet(func, |
| rise, |
| .533 * DEG_RAD, // Angular Diameter |
| 34 /60.0 * DEG_RAD, // Refraction correction |
| MINUTE_MS); // Desired accuracy |
| } |
| |
| //------------------------------------------------------------------------- |
| // Interpolation methods for finding the time at which a given event occurs |
| //------------------------------------------------------------------------- |
| |
| UDate CalendarAstronomer::timeOfAngle(AngleFunc& func, double desired, |
| double periodDays, double epsilon, UBool next) |
| { |
| // Find the value of the function at the current time |
| double lastAngle = func.eval(*this); |
| |
| // Find out how far we are from the desired angle |
| double deltaAngle = norm2PI(desired - lastAngle) ; |
| |
| // Using the average period, estimate the next (or previous) time at |
| // which the desired angle occurs. |
| double deltaT = (deltaAngle + (next ? 0.0 : - CalendarAstronomer_PI2 )) * (periodDays*DAY_MS) / CalendarAstronomer_PI2; |
| |
| double lastDeltaT = deltaT; // Liu |
| UDate startTime = fTime; // Liu |
| |
| setTime(fTime + uprv_ceil(deltaT)); |
| |
| // Now iterate until we get the error below epsilon. Throughout |
| // this loop we use normPI to get values in the range -Pi to Pi, |
| // since we're using them as correction factors rather than absolute angles. |
| do { |
| // Evaluate the function at the time we've estimated |
| double angle = func.eval(*this); |
| |
| // Find the # of milliseconds per radian at this point on the curve |
| double factor = uprv_fabs(deltaT / normPI(angle-lastAngle)); |
| |
| // Correct the time estimate based on how far off the angle is |
| deltaT = normPI(desired - angle) * factor; |
| |
| // HACK: |
| // |
| // If abs(deltaT) begins to diverge we need to quit this loop. |
| // This only appears to happen when attempting to locate, for |
| // example, a new moon on the day of the new moon. E.g.: |
| // |
| // This result is correct: |
| // newMoon(7508(Mon Jul 23 00:00:00 CST 1990,false))= |
| // Sun Jul 22 10:57:41 CST 1990 |
| // |
| // But attempting to make the same call a day earlier causes deltaT |
| // to diverge: |
| // CalendarAstronomer.timeOfAngle() diverging: 1.348508727575625E9 -> |
| // 1.3649828540224032E9 |
| // newMoon(7507(Sun Jul 22 00:00:00 CST 1990,false))= |
| // Sun Jul 08 13:56:15 CST 1990 |
| // |
| // As a temporary solution, we catch this specific condition and |
| // adjust our start time by one eighth period days (either forward |
| // or backward) and try again. |
| // Liu 11/9/00 |
| if (uprv_fabs(deltaT) > uprv_fabs(lastDeltaT)) { |
| double delta = uprv_ceil (periodDays * DAY_MS / 8.0); |
| setTime(startTime + (next ? delta : -delta)); |
| return timeOfAngle(func, desired, periodDays, epsilon, next); |
| } |
| |
| lastDeltaT = deltaT; |
| lastAngle = angle; |
| |
| setTime(fTime + uprv_ceil(deltaT)); |
| } |
| while (uprv_fabs(deltaT) > epsilon); |
| |
| return fTime; |
| } |
| |
| UDate CalendarAstronomer::riseOrSet(CoordFunc& func, UBool rise, |
| double diameter, double refraction, |
| double epsilon) |
| { |
| Equatorial pos; |
| double tanL = ::tan(fLatitude); |
| double deltaT = 0; |
| int32_t count = 0; |
| |
| // |
| // Calculate the object's position at the current time, then use that |
| // position to calculate the time of rising or setting. The position |
| // will be different at that time, so iterate until the error is allowable. |
| // |
| U_DEBUG_ASTRO_MSG(("setup rise=%s, dia=%.3lf, ref=%.3lf, eps=%.3lf\n", |
| rise?"T":"F", diameter, refraction, epsilon)); |
| do { |
| // See "Practical Astronomy With Your Calculator, section 33. |
| func.eval(pos, *this); |
| double angle = ::acos(-tanL * ::tan(pos.declination)); |
| double lst = ((rise ? CalendarAstronomer_PI2-angle : angle) + pos.ascension ) * 24 / CalendarAstronomer_PI2; |
| |
| // Convert from LST to Universal Time. |
| UDate newTime = lstToUT( lst ); |
| |
| deltaT = newTime - fTime; |
| setTime(newTime); |
| U_DEBUG_ASTRO_MSG(("%d] dT=%.3lf, angle=%.3lf, lst=%.3lf, A=%.3lf/D=%.3lf\n", |
| count, deltaT, angle, lst, pos.ascension, pos.declination)); |
| } |
| while (++ count < 5 && uprv_fabs(deltaT) > epsilon); |
| |
| // Calculate the correction due to refraction and the object's angular diameter |
| double cosD = ::cos(pos.declination); |
| double psi = ::acos(sin(fLatitude) / cosD); |
| double x = diameter / 2 + refraction; |
| double y = ::asin(sin(x) / ::sin(psi)); |
| long delta = (long)((240 * y * RAD_DEG / cosD)*SECOND_MS); |
| |
| return fTime + (rise ? -delta : delta); |
| } |
| /** |
| * 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 CalendarAstronomer::eclipticObliquity() { |
| if (isINVALID(eclipObliquity)) { |
| const double epoch = 2451545.0; // 2000 AD, January 1.5 |
| |
| double T = (getJulianDay() - epoch) / 36525; |
| |
| eclipObliquity = 23.439292 |
| - 46.815/3600 * T |
| - 0.0006/3600 * T*T |
| + 0.00181/3600 * T*T*T; |
| |
| eclipObliquity *= DEG_RAD; |
| } |
| return eclipObliquity; |
| } |
| |
| |
| //------------------------------------------------------------------------- |
| // Private data |
| //------------------------------------------------------------------------- |
| void CalendarAstronomer::clearCache() { |
| const double INVALID = uprv_getNaN(); |
| |
| julianDay = INVALID; |
| julianCentury = INVALID; |
| sunLongitude = INVALID; |
| meanAnomalySun = INVALID; |
| moonLongitude = INVALID; |
| moonEclipLong = INVALID; |
| meanAnomalyMoon = INVALID; |
| eclipObliquity = INVALID; |
| siderealTime = INVALID; |
| siderealT0 = INVALID; |
| moonPositionSet = FALSE; |
| } |
| |
| //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 CalendarAstronomer::local(UDate localMillis) { |
| // TODO - srl ? |
| TimeZone *tz = TimeZone::createDefault(); |
| int32_t rawOffset; |
| int32_t dstOffset; |
| UErrorCode status = U_ZERO_ERROR; |
| tz->getOffset(localMillis, TRUE, rawOffset, dstOffset, status); |
| delete tz; |
| return localMillis - rawOffset; |
| }*/ |
| |
| // Debugging functions |
| UnicodeString CalendarAstronomer::Ecliptic::toString() const |
| { |
| #ifdef U_DEBUG_ASTRO |
| char tmp[800]; |
| sprintf(tmp, "[%.5f,%.5f]", longitude*RAD_DEG, latitude*RAD_DEG); |
| return UnicodeString(tmp, ""); |
| #else |
| return UnicodeString(); |
| #endif |
| } |
| |
| UnicodeString CalendarAstronomer::Equatorial::toString() const |
| { |
| #ifdef U_DEBUG_ASTRO |
| char tmp[400]; |
| sprintf(tmp, "%f,%f", |
| (ascension*RAD_DEG), (declination*RAD_DEG)); |
| return UnicodeString(tmp, ""); |
| #else |
| return UnicodeString(); |
| #endif |
| } |
| |
| UnicodeString CalendarAstronomer::Horizon::toString() const |
| { |
| #ifdef U_DEBUG_ASTRO |
| char tmp[800]; |
| sprintf(tmp, "[%.5f,%.5f]", altitude*RAD_DEG, azimuth*RAD_DEG); |
| return UnicodeString(tmp, ""); |
| #else |
| return UnicodeString(); |
| #endif |
| } |
| |
| |
| // static private String radToHms(double angle) { |
| // int hrs = (int) (angle*RAD_HOUR); |
| // int min = (int)((angle*RAD_HOUR - hrs) * 60); |
| // int sec = (int)((angle*RAD_HOUR - hrs - min/60.0) * 3600); |
| |
| // return Integer.toString(hrs) + "h" + min + "m" + sec + "s"; |
| // } |
| |
| // static private String radToDms(double angle) { |
| // int deg = (int) (angle*RAD_DEG); |
| // int min = (int)((angle*RAD_DEG - deg) * 60); |
| // int sec = (int)((angle*RAD_DEG - deg - min/60.0) * 3600); |
| |
| // return Integer.toString(deg) + "\u00b0" + min + "'" + sec + "\""; |
| // } |
| |
| // =============== Calendar Cache ================ |
| |
| void CalendarCache::createCache(CalendarCache** cache, UErrorCode& status) { |
| ucln_i18n_registerCleanup(UCLN_I18N_ASTRO_CALENDAR, calendar_astro_cleanup); |
| if(cache == NULL) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| } else { |
| *cache = new CalendarCache(32, status); |
| if(U_FAILURE(status)) { |
| delete *cache; |
| *cache = NULL; |
| } |
| } |
| } |
| |
| int32_t CalendarCache::get(CalendarCache** cache, int32_t key, UErrorCode &status) { |
| int32_t res; |
| |
| if(U_FAILURE(status)) { |
| return 0; |
| } |
| umtx_lock(&ccLock); |
| |
| if(*cache == NULL) { |
| createCache(cache, status); |
| if(U_FAILURE(status)) { |
| umtx_unlock(&ccLock); |
| return 0; |
| } |
| } |
| |
| res = uhash_igeti((*cache)->fTable, key); |
| U_DEBUG_ASTRO_MSG(("%p: GET: [%d] == %d\n", (*cache)->fTable, key, res)); |
| |
| umtx_unlock(&ccLock); |
| return res; |
| } |
| |
| void CalendarCache::put(CalendarCache** cache, int32_t key, int32_t value, UErrorCode &status) { |
| if(U_FAILURE(status)) { |
| return; |
| } |
| umtx_lock(&ccLock); |
| |
| if(*cache == NULL) { |
| createCache(cache, status); |
| if(U_FAILURE(status)) { |
| umtx_unlock(&ccLock); |
| return; |
| } |
| } |
| |
| uhash_iputi((*cache)->fTable, key, value, &status); |
| U_DEBUG_ASTRO_MSG(("%p: PUT: [%d] := %d\n", (*cache)->fTable, key, value)); |
| |
| umtx_unlock(&ccLock); |
| } |
| |
| CalendarCache::CalendarCache(int32_t size, UErrorCode &status) { |
| fTable = uhash_openSize(uhash_hashLong, uhash_compareLong, NULL, size, &status); |
| U_DEBUG_ASTRO_MSG(("%p: Opening.\n", fTable)); |
| } |
| |
| CalendarCache::~CalendarCache() { |
| if(fTable != NULL) { |
| U_DEBUG_ASTRO_MSG(("%p: Closing.\n", fTable)); |
| uhash_close(fTable); |
| } |
| } |
| |
| U_NAMESPACE_END |
| |
| #endif // !UCONFIG_NO_FORMATTING |