The Tor Browser: intl/icu/source/i18n/astro.cpp@fc2d59ddac77 (annotated)

intl/icu/source/i18n/astro.cpp@fc2d59ddac77 (annotated)

intl/icu/source/i18n/astro.cpp

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /************************************************************************
  * 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
 . /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
 /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

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intl/icu/source/i18n/astro.cpp@fc2d59ddac77 (annotated)

intl/icu/source/i18n/astro.cpp