1/************************************************************************ 2 * Copyright (C) 1996-2012, International Business Machines Corporation 3 * and others. All Rights Reserved. 4 ************************************************************************ 5 * 2003-nov-07 srl Port from Java 6 */ 7 8#include "astro.h" 9 10#if !UCONFIG_NO_FORMATTING 11 12#include "unicode/calendar.h" 13#include <math.h> 14#include <float.h> 15#include "unicode/putil.h" 16#include "uhash.h" 17#include "umutex.h" 18#include "ucln_in.h" 19#include "putilimp.h" 20#include <stdio.h> // for toString() 21 22#if defined (PI) 23#undef PI 24#endif 25 26#ifdef U_DEBUG_ASTRO 27# include "uresimp.h" // for debugging 28 29static void debug_astro_loc(const char *f, int32_t l) 30{ 31 fprintf(stderr, "%s:%d: ", f, l); 32} 33 34static void debug_astro_msg(const char *pat, ...) 35{ 36 va_list ap; 37 va_start(ap, pat); 38 vfprintf(stderr, pat, ap); 39 fflush(stderr); 40} 41#include "unicode/datefmt.h" 42#include "unicode/ustring.h" 43static const char * debug_astro_date(UDate d) { 44 static char gStrBuf[1024]; 45 static DateFormat *df = NULL; 46 if(df == NULL) { 47 df = DateFormat::createDateTimeInstance(DateFormat::MEDIUM, DateFormat::MEDIUM, Locale::getUS()); 48 df->adoptTimeZone(TimeZone::getGMT()->clone()); 49 } 50 UnicodeString str; 51 df->format(d,str); 52 u_austrncpy(gStrBuf,str.getTerminatedBuffer(),sizeof(gStrBuf)-1); 53 return gStrBuf; 54} 55 56// must use double parens, i.e.: U_DEBUG_ASTRO_MSG(("four is: %d",4)); 57#define U_DEBUG_ASTRO_MSG(x) {debug_astro_loc(__FILE__,__LINE__);debug_astro_msg x;} 58#else 59#define U_DEBUG_ASTRO_MSG(x) 60#endif 61 62static inline UBool isINVALID(double d) { 63 return(uprv_isNaN(d)); 64} 65 66static UMutex ccLock = U_MUTEX_INITIALIZER; 67 68U_CDECL_BEGIN 69static UBool calendar_astro_cleanup(void) { 70 return TRUE; 71} 72U_CDECL_END 73 74U_NAMESPACE_BEGIN 75 76/** 77 * The number of standard hours in one sidereal day. 78 * Approximately 24.93. 79 * @internal 80 * @deprecated ICU 2.4. This class may be removed or modified. 81 */ 82#define SIDEREAL_DAY (23.93446960027) 83 84/** 85 * The number of sidereal hours in one mean solar day. 86 * Approximately 24.07. 87 * @internal 88 * @deprecated ICU 2.4. This class may be removed or modified. 89 */ 90#define SOLAR_DAY (24.065709816) 91 92/** 93 * The average number of solar days from one new moon to the next. This is the time 94 * it takes for the moon to return the same ecliptic longitude as the sun. 95 * It is longer than the sidereal month because the sun's longitude increases 96 * during the year due to the revolution of the earth around the sun. 97 * Approximately 29.53. 98 * 99 * @see #SIDEREAL_MONTH 100 * @internal 101 * @deprecated ICU 2.4. This class may be removed or modified. 102 */ 103const double CalendarAstronomer::SYNODIC_MONTH = 29.530588853; 104 105/** 106 * The average number of days it takes 107 * for the moon to return to the same ecliptic longitude relative to the 108 * stellar background. This is referred to as the sidereal month. 109 * It is shorter than the synodic month due to 110 * the revolution of the earth around the sun. 111 * Approximately 27.32. 112 * 113 * @see #SYNODIC_MONTH 114 * @internal 115 * @deprecated ICU 2.4. This class may be removed or modified. 116 */ 117#define SIDEREAL_MONTH 27.32166 118 119/** 120 * The average number number of days between successive vernal equinoxes. 121 * Due to the precession of the earth's 122 * axis, this is not precisely the same as the sidereal year. 123 * Approximately 365.24 124 * 125 * @see #SIDEREAL_YEAR 126 * @internal 127 * @deprecated ICU 2.4. This class may be removed or modified. 128 */ 129#define TROPICAL_YEAR 365.242191 130 131/** 132 * The average number of days it takes 133 * for the sun to return to the same position against the fixed stellar 134 * background. This is the duration of one orbit of the earth about the sun 135 * as it would appear to an outside observer. 136 * Due to the precession of the earth's 137 * axis, this is not precisely the same as the tropical year. 138 * Approximately 365.25. 139 * 140 * @see #TROPICAL_YEAR 141 * @internal 142 * @deprecated ICU 2.4. This class may be removed or modified. 143 */ 144#define SIDEREAL_YEAR 365.25636 145 146//------------------------------------------------------------------------- 147// Time-related constants 148//------------------------------------------------------------------------- 149 150/** 151 * The number of milliseconds in one second. 152 * @internal 153 * @deprecated ICU 2.4. This class may be removed or modified. 154 */ 155#define SECOND_MS U_MILLIS_PER_SECOND 156 157/** 158 * The number of milliseconds in one minute. 159 * @internal 160 * @deprecated ICU 2.4. This class may be removed or modified. 161 */ 162#define MINUTE_MS U_MILLIS_PER_MINUTE 163 164/** 165 * The number of milliseconds in one hour. 166 * @internal 167 * @deprecated ICU 2.4. This class may be removed or modified. 168 */ 169#define HOUR_MS U_MILLIS_PER_HOUR 170 171/** 172 * The number of milliseconds in one day. 173 * @internal 174 * @deprecated ICU 2.4. This class may be removed or modified. 175 */ 176#define DAY_MS U_MILLIS_PER_DAY 177 178/** 179 * The start of the julian day numbering scheme used by astronomers, which 180 * is 1/1/4713 BC (Julian), 12:00 GMT. This is given as the number of milliseconds 181 * since 1/1/1970 AD (Gregorian), a negative number. 182 * Note that julian day numbers and 183 * the Julian calendar are <em>not</em> the same thing. Also note that 184 * julian days start at <em>noon</em>, not midnight. 185 * @internal 186 * @deprecated ICU 2.4. This class may be removed or modified. 187 */ 188#define JULIAN_EPOCH_MS -210866760000000.0 189 190 191/** 192 * Milliseconds value for 0.0 January 2000 AD. 193 */ 194#define EPOCH_2000_MS 946598400000.0 195 196//------------------------------------------------------------------------- 197// Assorted private data used for conversions 198//------------------------------------------------------------------------- 199 200// My own copies of these so compilers are more likely to optimize them away 201const double CalendarAstronomer::PI = 3.14159265358979323846; 202 203#define CalendarAstronomer_PI2 (CalendarAstronomer::PI*2.0) 204#define RAD_HOUR ( 12 / CalendarAstronomer::PI ) // radians -> hours 205#define DEG_RAD ( CalendarAstronomer::PI / 180 ) // degrees -> radians 206#define RAD_DEG ( 180 / CalendarAstronomer::PI ) // radians -> degrees 207 208/*** 209 * Given 'value', add or subtract 'range' until 0 <= 'value' < range. 210 * The modulus operator. 211 */ 212inline static double normalize(double value, double range) { 213 return value - range * ClockMath::floorDivide(value, range); 214} 215 216/** 217 * Normalize an angle so that it's in the range 0 - 2pi. 218 * For positive angles this is just (angle % 2pi), but the Java 219 * mod operator doesn't work that way for negative numbers.... 220 */ 221inline static double norm2PI(double angle) { 222 return normalize(angle, CalendarAstronomer::PI * 2.0); 223} 224 225/** 226 * Normalize an angle into the range -PI - PI 227 */ 228inline static double normPI(double angle) { 229 return normalize(angle + CalendarAstronomer::PI, CalendarAstronomer::PI * 2.0) - CalendarAstronomer::PI; 230} 231 232//------------------------------------------------------------------------- 233// Constructors 234//------------------------------------------------------------------------- 235 236/** 237 * Construct a new <code>CalendarAstronomer</code> object that is initialized to 238 * the current date and time. 239 * @internal 240 * @deprecated ICU 2.4. This class may be removed or modified. 241 */ 242CalendarAstronomer::CalendarAstronomer(): 243 fTime(Calendar::getNow()), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(FALSE) { 244 clearCache(); 245} 246 247/** 248 * Construct a new <code>CalendarAstronomer</code> object that is initialized to 249 * the specified date and time. 250 * @internal 251 * @deprecated ICU 2.4. This class may be removed or modified. 252 */ 253CalendarAstronomer::CalendarAstronomer(UDate d): fTime(d), fLongitude(0.0), fLatitude(0.0), fGmtOffset(0.0), moonPosition(0,0), moonPositionSet(FALSE) { 254 clearCache(); 255} 256 257/** 258 * Construct a new <code>CalendarAstronomer</code> object with the given 259 * latitude and longitude. The object's time is set to the current 260 * date and time. 261 * <p> 262 * @param longitude The desired longitude, in <em>degrees</em> east of 263 * the Greenwich meridian. 264 * 265 * @param latitude The desired latitude, in <em>degrees</em>. Positive 266 * values signify North, negative South. 267 * 268 * @see java.util.Date#getTime() 269 * @internal 270 * @deprecated ICU 2.4. This class may be removed or modified. 271 */ 272CalendarAstronomer::CalendarAstronomer(double longitude, double latitude) : 273 fTime(Calendar::getNow()), moonPosition(0,0), moonPositionSet(FALSE) { 274 fLongitude = normPI(longitude * (double)DEG_RAD); 275 fLatitude = normPI(latitude * (double)DEG_RAD); 276 fGmtOffset = (double)(fLongitude * 24. * (double)HOUR_MS / (double)CalendarAstronomer_PI2); 277 clearCache(); 278} 279 280CalendarAstronomer::~CalendarAstronomer() 281{ 282} 283 284//------------------------------------------------------------------------- 285// Time and date getters and setters 286//------------------------------------------------------------------------- 287 288/** 289 * Set the current date and time of this <code>CalendarAstronomer</code> object. All 290 * astronomical calculations are performed based on this time setting. 291 * 292 * @param aTime the date and time, expressed as the number of milliseconds since 293 * 1/1/1970 0:00 GMT (Gregorian). 294 * 295 * @see #setDate 296 * @see #getTime 297 * @internal 298 * @deprecated ICU 2.4. This class may be removed or modified. 299 */ 300void CalendarAstronomer::setTime(UDate aTime) { 301 fTime = aTime; 302 U_DEBUG_ASTRO_MSG(("setTime(%.1lf, %sL)\n", aTime, debug_astro_date(aTime+fGmtOffset))); 303 clearCache(); 304} 305 306/** 307 * Set the current date and time of this <code>CalendarAstronomer</code> object. All 308 * astronomical calculations are performed based on this time setting. 309 * 310 * @param jdn the desired time, expressed as a "julian day number", 311 * which is the number of elapsed days since 312 * 1/1/4713 BC (Julian), 12:00 GMT. Note that julian day 313 * numbers start at <em>noon</em>. To get the jdn for 314 * the corresponding midnight, subtract 0.5. 315 * 316 * @see #getJulianDay 317 * @see #JULIAN_EPOCH_MS 318 * @internal 319 * @deprecated ICU 2.4. This class may be removed or modified. 320 */ 321void CalendarAstronomer::setJulianDay(double jdn) { 322 fTime = (double)(jdn * DAY_MS) + JULIAN_EPOCH_MS; 323 clearCache(); 324 julianDay = jdn; 325} 326 327/** 328 * Get the current time of this <code>CalendarAstronomer</code> object, 329 * represented as the number of milliseconds since 330 * 1/1/1970 AD 0:00 GMT (Gregorian). 331 * 332 * @see #setTime 333 * @see #getDate 334 * @internal 335 * @deprecated ICU 2.4. This class may be removed or modified. 336 */ 337UDate CalendarAstronomer::getTime() { 338 return fTime; 339} 340 341/** 342 * Get the current time of this <code>CalendarAstronomer</code> object, 343 * expressed as a "julian day number", which is the number of elapsed 344 * days since 1/1/4713 BC (Julian), 12:00 GMT. 345 * 346 * @see #setJulianDay 347 * @see #JULIAN_EPOCH_MS 348 * @internal 349 * @deprecated ICU 2.4. This class may be removed or modified. 350 */ 351double CalendarAstronomer::getJulianDay() { 352 if (isINVALID(julianDay)) { 353 julianDay = (fTime - (double)JULIAN_EPOCH_MS) / (double)DAY_MS; 354 } 355 return julianDay; 356} 357 358/** 359 * Return this object's time expressed in julian centuries: 360 * the number of centuries after 1/1/1900 AD, 12:00 GMT 361 * 362 * @see #getJulianDay 363 * @internal 364 * @deprecated ICU 2.4. This class may be removed or modified. 365 */ 366double CalendarAstronomer::getJulianCentury() { 367 if (isINVALID(julianCentury)) { 368 julianCentury = (getJulianDay() - 2415020.0) / 36525.0; 369 } 370 return julianCentury; 371} 372 373/** 374 * Returns the current Greenwich sidereal time, measured in hours 375 * @internal 376 * @deprecated ICU 2.4. This class may be removed or modified. 377 */ 378double CalendarAstronomer::getGreenwichSidereal() { 379 if (isINVALID(siderealTime)) { 380 // See page 86 of "Practial Astronomy with your Calculator", 381 // by Peter Duffet-Smith, for details on the algorithm. 382 383 double UT = normalize(fTime/(double)HOUR_MS, 24.); 384 385 siderealTime = normalize(getSiderealOffset() + UT*1.002737909, 24.); 386 } 387 return siderealTime; 388} 389 390double CalendarAstronomer::getSiderealOffset() { 391 if (isINVALID(siderealT0)) { 392 double JD = uprv_floor(getJulianDay() - 0.5) + 0.5; 393 double S = JD - 2451545.0; 394 double T = S / 36525.0; 395 siderealT0 = normalize(6.697374558 + 2400.051336*T + 0.000025862*T*T, 24); 396 } 397 return siderealT0; 398} 399 400/** 401 * Returns the current local sidereal time, measured in hours 402 * @internal 403 * @deprecated ICU 2.4. This class may be removed or modified. 404 */ 405double CalendarAstronomer::getLocalSidereal() { 406 return normalize(getGreenwichSidereal() + (fGmtOffset/(double)HOUR_MS), 24.); 407} 408 409/** 410 * Converts local sidereal time to Universal Time. 411 * 412 * @param lst The Local Sidereal Time, in hours since sidereal midnight 413 * on this object's current date. 414 * 415 * @return The corresponding Universal Time, in milliseconds since 416 * 1 Jan 1970, GMT. 417 */ 418double CalendarAstronomer::lstToUT(double lst) { 419 // Convert to local mean time 420 double lt = normalize((lst - getSiderealOffset()) * 0.9972695663, 24); 421 422 // Then find local midnight on this day 423 double base = (DAY_MS * ClockMath::floorDivide(fTime + fGmtOffset,(double)DAY_MS)) - fGmtOffset; 424 425 //out(" lt =" + lt + " hours"); 426 //out(" base=" + new Date(base)); 427 428 return base + (long)(lt * HOUR_MS); 429} 430 431 432//------------------------------------------------------------------------- 433// Coordinate transformations, all based on the current time of this object 434//------------------------------------------------------------------------- 435 436/** 437 * Convert from ecliptic to equatorial coordinates. 438 * 439 * @param ecliptic A point in the sky in ecliptic coordinates. 440 * @return The corresponding point in equatorial coordinates. 441 * @internal 442 * @deprecated ICU 2.4. This class may be removed or modified. 443 */ 444CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, const CalendarAstronomer::Ecliptic& ecliptic) 445{ 446 return eclipticToEquatorial(result, ecliptic.longitude, ecliptic.latitude); 447} 448 449/** 450 * Convert from ecliptic to equatorial coordinates. 451 * 452 * @param eclipLong The ecliptic longitude 453 * @param eclipLat The ecliptic latitude 454 * 455 * @return The corresponding point in equatorial coordinates. 456 * @internal 457 * @deprecated ICU 2.4. This class may be removed or modified. 458 */ 459CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong, double eclipLat) 460{ 461 // See page 42 of "Practial Astronomy with your Calculator", 462 // by Peter Duffet-Smith, for details on the algorithm. 463 464 double obliq = eclipticObliquity(); 465 double sinE = ::sin(obliq); 466 double cosE = cos(obliq); 467 468 double sinL = ::sin(eclipLong); 469 double cosL = cos(eclipLong); 470 471 double sinB = ::sin(eclipLat); 472 double cosB = cos(eclipLat); 473 double tanB = tan(eclipLat); 474 475 result.set(atan2(sinL*cosE - tanB*sinE, cosL), 476 asin(sinB*cosE + cosB*sinE*sinL) ); 477 return result; 478} 479 480/** 481 * Convert from ecliptic longitude to equatorial coordinates. 482 * 483 * @param eclipLong The ecliptic longitude 484 * 485 * @return The corresponding point in equatorial coordinates. 486 * @internal 487 * @deprecated ICU 2.4. This class may be removed or modified. 488 */ 489CalendarAstronomer::Equatorial& CalendarAstronomer::eclipticToEquatorial(CalendarAstronomer::Equatorial& result, double eclipLong) 490{ 491 return eclipticToEquatorial(result, eclipLong, 0); // TODO: optimize 492} 493 494/** 495 * @internal 496 * @deprecated ICU 2.4. This class may be removed or modified. 497 */ 498CalendarAstronomer::Horizon& CalendarAstronomer::eclipticToHorizon(CalendarAstronomer::Horizon& result, double eclipLong) 499{ 500 Equatorial equatorial; 501 eclipticToEquatorial(equatorial, eclipLong); 502 503 double H = getLocalSidereal()*CalendarAstronomer::PI/12 - equatorial.ascension; // Hour-angle 504 505 double sinH = ::sin(H); 506 double cosH = cos(H); 507 double sinD = ::sin(equatorial.declination); 508 double cosD = cos(equatorial.declination); 509 double sinL = ::sin(fLatitude); 510 double cosL = cos(fLatitude); 511 512 double altitude = asin(sinD*sinL + cosD*cosL*cosH); 513 double azimuth = atan2(-cosD*cosL*sinH, sinD - sinL * ::sin(altitude)); 514 515 result.set(azimuth, altitude); 516 return result; 517} 518 519 520//------------------------------------------------------------------------- 521// The Sun 522//------------------------------------------------------------------------- 523 524// 525// Parameters of the Sun's orbit as of the epoch Jan 0.0 1990 526// Angles are in radians (after multiplying by CalendarAstronomer::PI/180) 527// 528#define JD_EPOCH 2447891.5 // Julian day of epoch 529 530#define SUN_ETA_G (279.403303 * CalendarAstronomer::PI/180) // Ecliptic longitude at epoch 531#define SUN_OMEGA_G (282.768422 * CalendarAstronomer::PI/180) // Ecliptic longitude of perigee 532#define SUN_E 0.016713 // Eccentricity of orbit 533//double sunR0 1.495585e8 // Semi-major axis in KM 534//double sunTheta0 (0.533128 * CalendarAstronomer::PI/180) // Angular diameter at R0 535 536// The following three methods, which compute the sun parameters 537// given above for an arbitrary epoch (whatever time the object is 538// set to), make only a small difference as compared to using the 539// above constants. E.g., Sunset times might differ by ~12 540// seconds. Furthermore, the eta-g computation is befuddled by 541// Duffet-Smith's incorrect coefficients (p.86). I've corrected 542// the first-order coefficient but the others may be off too - no 543// way of knowing without consulting another source. 544 545// /** 546// * Return the sun's ecliptic longitude at perigee for the current time. 547// * See Duffett-Smith, p. 86. 548// * @return radians 549// */ 550// private double getSunOmegaG() { 551// double T = getJulianCentury(); 552// return (281.2208444 + (1.719175 + 0.000452778*T)*T) * DEG_RAD; 553// } 554 555// /** 556// * Return the sun's ecliptic longitude for the current time. 557// * See Duffett-Smith, p. 86. 558// * @return radians 559// */ 560// private double getSunEtaG() { 561// double T = getJulianCentury(); 562// //return (279.6966778 + (36000.76892 + 0.0003025*T)*T) * DEG_RAD; 563// // 564// // The above line is from Duffett-Smith, and yields manifestly wrong 565// // results. The below constant is derived empirically to match the 566// // constant he gives for the 1990 EPOCH. 567// // 568// return (279.6966778 + (-0.3262541582718024 + 0.0003025*T)*T) * DEG_RAD; 569// } 570 571// /** 572// * Return the sun's eccentricity of orbit for the current time. 573// * See Duffett-Smith, p. 86. 574// * @return double 575// */ 576// private double getSunE() { 577// double T = getJulianCentury(); 578// return 0.01675104 - (0.0000418 + 0.000000126*T)*T; 579// } 580 581/** 582 * Find the "true anomaly" (longitude) of an object from 583 * its mean anomaly and the eccentricity of its orbit. This uses 584 * an iterative solution to Kepler's equation. 585 * 586 * @param meanAnomaly The object's longitude calculated as if it were in 587 * a regular, circular orbit, measured in radians 588 * from the point of perigee. 589 * 590 * @param eccentricity The eccentricity of the orbit 591 * 592 * @return The true anomaly (longitude) measured in radians 593 */ 594static double trueAnomaly(double meanAnomaly, double eccentricity) 595{ 596 // First, solve Kepler's equation iteratively 597 // Duffett-Smith, p.90 598 double delta; 599 double E = meanAnomaly; 600 do { 601 delta = E - eccentricity * ::sin(E) - meanAnomaly; 602 E = E - delta / (1 - eccentricity * ::cos(E)); 603 } 604 while (uprv_fabs(delta) > 1e-5); // epsilon = 1e-5 rad 605 606 return 2.0 * ::atan( ::tan(E/2) * ::sqrt( (1+eccentricity) 607 /(1-eccentricity) ) ); 608} 609 610/** 611 * The longitude of the sun at the time specified by this object. 612 * The longitude is measured in radians along the ecliptic 613 * from the "first point of Aries," the point at which the ecliptic 614 * crosses the earth's equatorial plane at the vernal equinox. 615 * <p> 616 * Currently, this method uses an approximation of the two-body Kepler's 617 * equation for the earth and the sun. It does not take into account the 618 * perturbations caused by the other planets, the moon, etc. 619 * @internal 620 * @deprecated ICU 2.4. This class may be removed or modified. 621 */ 622double CalendarAstronomer::getSunLongitude() 623{ 624 // See page 86 of "Practial Astronomy with your Calculator", 625 // by Peter Duffet-Smith, for details on the algorithm. 626 627 if (isINVALID(sunLongitude)) { 628 getSunLongitude(getJulianDay(), sunLongitude, meanAnomalySun); 629 } 630 return sunLongitude; 631} 632 633/** 634 * TODO Make this public when the entire class is package-private. 635 */ 636/*public*/ void CalendarAstronomer::getSunLongitude(double jDay, double &longitude, double &meanAnomaly) 637{ 638 // See page 86 of "Practial Astronomy with your Calculator", 639 // by Peter Duffet-Smith, for details on the algorithm. 640 641 double day = jDay - JD_EPOCH; // Days since epoch 642 643 // Find the angular distance the sun in a fictitious 644 // circular orbit has travelled since the epoch. 645 double epochAngle = norm2PI(CalendarAstronomer_PI2/TROPICAL_YEAR*day); 646 647 // The epoch wasn't at the sun's perigee; find the angular distance 648 // since perigee, which is called the "mean anomaly" 649 meanAnomaly = norm2PI(epochAngle + SUN_ETA_G - SUN_OMEGA_G); 650 651 // Now find the "true anomaly", e.g. the real solar longitude 652 // by solving Kepler's equation for an elliptical orbit 653 // NOTE: The 3rd ed. of the book lists omega_g and eta_g in different 654 // equations; omega_g is to be correct. 655 longitude = norm2PI(trueAnomaly(meanAnomaly, SUN_E) + SUN_OMEGA_G); 656} 657 658/** 659 * The position of the sun at this object's current date and time, 660 * in equatorial coordinates. 661 * @internal 662 * @deprecated ICU 2.4. This class may be removed or modified. 663 */ 664CalendarAstronomer::Equatorial& CalendarAstronomer::getSunPosition(CalendarAstronomer::Equatorial& result) { 665 return eclipticToEquatorial(result, getSunLongitude(), 0); 666} 667 668 669/** 670 * Constant representing the vernal equinox. 671 * For use with {@link #getSunTime getSunTime}. 672 * Note: In this case, "vernal" refers to the northern hemisphere's seasons. 673 * @internal 674 * @deprecated ICU 2.4. This class may be removed or modified. 675 */ 676/*double CalendarAstronomer::VERNAL_EQUINOX() { 677 return 0; 678}*/ 679 680/** 681 * Constant representing the summer solstice. 682 * For use with {@link #getSunTime getSunTime}. 683 * Note: In this case, "summer" refers to the northern hemisphere's seasons. 684 * @internal 685 * @deprecated ICU 2.4. This class may be removed or modified. 686 */ 687double CalendarAstronomer::SUMMER_SOLSTICE() { 688 return (CalendarAstronomer::PI/2); 689} 690 691/** 692 * Constant representing the autumnal equinox. 693 * For use with {@link #getSunTime getSunTime}. 694 * Note: In this case, "autumn" refers to the northern hemisphere's seasons. 695 * @internal 696 * @deprecated ICU 2.4. This class may be removed or modified. 697 */ 698/*double CalendarAstronomer::AUTUMN_EQUINOX() { 699 return (CalendarAstronomer::PI); 700}*/ 701 702/** 703 * Constant representing the winter solstice. 704 * For use with {@link #getSunTime getSunTime}. 705 * Note: In this case, "winter" refers to the northern hemisphere's seasons. 706 * @internal 707 * @deprecated ICU 2.4. This class may be removed or modified. 708 */ 709double CalendarAstronomer::WINTER_SOLSTICE() { 710 return ((CalendarAstronomer::PI*3)/2); 711} 712 713CalendarAstronomer::AngleFunc::~AngleFunc() {} 714 715/** 716 * Find the next time at which the sun's ecliptic longitude will have 717 * the desired value. 718 * @internal 719 * @deprecated ICU 2.4. This class may be removed or modified. 720 */ 721class SunTimeAngleFunc : public CalendarAstronomer::AngleFunc { 722public: 723 virtual ~SunTimeAngleFunc(); 724 virtual double eval(CalendarAstronomer& a) { return a.getSunLongitude(); } 725}; 726 727SunTimeAngleFunc::~SunTimeAngleFunc() {} 728 729UDate CalendarAstronomer::getSunTime(double desired, UBool next) 730{ 731 SunTimeAngleFunc func; 732 return timeOfAngle( func, 733 desired, 734 TROPICAL_YEAR, 735 MINUTE_MS, 736 next); 737} 738 739CalendarAstronomer::CoordFunc::~CoordFunc() {} 740 741class RiseSetCoordFunc : public CalendarAstronomer::CoordFunc { 742public: 743 virtual ~RiseSetCoordFunc(); 744 virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { a.getSunPosition(result); } 745}; 746 747RiseSetCoordFunc::~RiseSetCoordFunc() {} 748 749UDate CalendarAstronomer::getSunRiseSet(UBool rise) 750{ 751 UDate t0 = fTime; 752 753 // Make a rough guess: 6am or 6pm local time on the current day 754 double noon = ClockMath::floorDivide(fTime + fGmtOffset, (double)DAY_MS)*DAY_MS - fGmtOffset + (12*HOUR_MS); 755 756 U_DEBUG_ASTRO_MSG(("Noon=%.2lf, %sL, gmtoff %.2lf\n", noon, debug_astro_date(noon+fGmtOffset), fGmtOffset)); 757 setTime(noon + ((rise ? -6 : 6) * HOUR_MS)); 758 U_DEBUG_ASTRO_MSG(("added %.2lf ms as a guess,\n", ((rise ? -6. : 6.) * HOUR_MS))); 759 760 RiseSetCoordFunc func; 761 double t = riseOrSet(func, 762 rise, 763 .533 * DEG_RAD, // Angular Diameter 764 34. /60.0 * DEG_RAD, // Refraction correction 765 MINUTE_MS / 12.); // Desired accuracy 766 767 setTime(t0); 768 return t; 769} 770 771// Commented out - currently unused. ICU 2.6, Alan 772// //------------------------------------------------------------------------- 773// // Alternate Sun Rise/Set 774// // See Duffett-Smith p.93 775// //------------------------------------------------------------------------- 776// 777// // This yields worse results (as compared to USNO data) than getSunRiseSet(). 778// /** 779// * TODO Make this when the entire class is package-private. 780// */ 781// /*public*/ long getSunRiseSet2(boolean rise) { 782// // 1. Calculate coordinates of the sun's center for midnight 783// double jd = uprv_floor(getJulianDay() - 0.5) + 0.5; 784// double[] sl = getSunLongitude(jd);// double lambda1 = sl[0]; 785// Equatorial pos1 = eclipticToEquatorial(lambda1, 0); 786// 787// // 2. Add ... to lambda to get position 24 hours later 788// double lambda2 = lambda1 + 0.985647*DEG_RAD; 789// Equatorial pos2 = eclipticToEquatorial(lambda2, 0); 790// 791// // 3. Calculate LSTs of rising and setting for these two positions 792// double tanL = ::tan(fLatitude); 793// double H = ::acos(-tanL * ::tan(pos1.declination)); 794// double lst1r = (CalendarAstronomer_PI2 + pos1.ascension - H) * 24 / CalendarAstronomer_PI2; 795// double lst1s = (pos1.ascension + H) * 24 / CalendarAstronomer_PI2; 796// H = ::acos(-tanL * ::tan(pos2.declination)); 797// double lst2r = (CalendarAstronomer_PI2-H + pos2.ascension ) * 24 / CalendarAstronomer_PI2; 798// double lst2s = (H + pos2.ascension ) * 24 / CalendarAstronomer_PI2; 799// if (lst1r > 24) lst1r -= 24; 800// if (lst1s > 24) lst1s -= 24; 801// if (lst2r > 24) lst2r -= 24; 802// if (lst2s > 24) lst2s -= 24; 803// 804// // 4. Convert LSTs to GSTs. If GST1 > GST2, add 24 to GST2. 805// double gst1r = lstToGst(lst1r); 806// double gst1s = lstToGst(lst1s); 807// double gst2r = lstToGst(lst2r); 808// double gst2s = lstToGst(lst2s); 809// if (gst1r > gst2r) gst2r += 24; 810// if (gst1s > gst2s) gst2s += 24; 811// 812// // 5. Calculate GST at 0h UT of this date 813// double t00 = utToGst(0); 814// 815// // 6. Calculate GST at 0h on the observer's longitude 816// double offset = ::round(fLongitude*12/PI); // p.95 step 6; he _rounds_ to nearest 15 deg. 817// double t00p = t00 - offset*1.002737909; 818// if (t00p < 0) t00p += 24; // do NOT normalize 819// 820// // 7. Adjust 821// if (gst1r < t00p) { 822// gst1r += 24; 823// gst2r += 24; 824// } 825// if (gst1s < t00p) { 826// gst1s += 24; 827// gst2s += 24; 828// } 829// 830// // 8. 831// double gstr = (24.07*gst1r-t00*(gst2r-gst1r))/(24.07+gst1r-gst2r); 832// double gsts = (24.07*gst1s-t00*(gst2s-gst1s))/(24.07+gst1s-gst2s); 833// 834// // 9. Correct for parallax, refraction, and sun's diameter 835// double dec = (pos1.declination + pos2.declination) / 2; 836// double psi = ::acos(sin(fLatitude) / cos(dec)); 837// double x = 0.830725 * DEG_RAD; // parallax+refraction+diameter 838// double y = ::asin(sin(x) / ::sin(psi)) * RAD_DEG; 839// double delta_t = 240 * y / cos(dec) / 3600; // hours 840// 841// // 10. Add correction to GSTs, subtract from GSTr 842// gstr -= delta_t; 843// gsts += delta_t; 844// 845// // 11. Convert GST to UT and then to local civil time 846// double ut = gstToUt(rise ? gstr : gsts); 847// //System.out.println((rise?"rise=":"set=") + ut + ", delta_t=" + delta_t); 848// long midnight = DAY_MS * (time / DAY_MS); // Find UT midnight on this day 849// return midnight + (long) (ut * 3600000); 850// } 851 852// Commented out - currently unused. ICU 2.6, Alan 853// /** 854// * Convert local sidereal time to Greenwich sidereal time. 855// * Section 15. Duffett-Smith p.21 856// * @param lst in hours (0..24) 857// * @return GST in hours (0..24) 858// */ 859// double lstToGst(double lst) { 860// double delta = fLongitude * 24 / CalendarAstronomer_PI2; 861// return normalize(lst - delta, 24); 862// } 863 864// Commented out - currently unused. ICU 2.6, Alan 865// /** 866// * Convert UT to GST on this date. 867// * Section 12. Duffett-Smith p.17 868// * @param ut in hours 869// * @return GST in hours 870// */ 871// double utToGst(double ut) { 872// return normalize(getT0() + ut*1.002737909, 24); 873// } 874 875// Commented out - currently unused. ICU 2.6, Alan 876// /** 877// * Convert GST to UT on this date. 878// * Section 13. Duffett-Smith p.18 879// * @param gst in hours 880// * @return UT in hours 881// */ 882// double gstToUt(double gst) { 883// return normalize(gst - getT0(), 24) * 0.9972695663; 884// } 885 886// Commented out - currently unused. ICU 2.6, Alan 887// double getT0() { 888// // Common computation for UT <=> GST 889// 890// // Find JD for 0h UT 891// double jd = uprv_floor(getJulianDay() - 0.5) + 0.5; 892// 893// double s = jd - 2451545.0; 894// double t = s / 36525.0; 895// double t0 = 6.697374558 + (2400.051336 + 0.000025862*t)*t; 896// return t0; 897// } 898 899// Commented out - currently unused. ICU 2.6, Alan 900// //------------------------------------------------------------------------- 901// // Alternate Sun Rise/Set 902// // See sci.astro FAQ 903// // http://www.faqs.org/faqs/astronomy/faq/part3/section-5.html 904// //------------------------------------------------------------------------- 905// 906// // Note: This method appears to produce inferior accuracy as 907// // compared to getSunRiseSet(). 908// 909// /** 910// * TODO Make this when the entire class is package-private. 911// */ 912// /*public*/ long getSunRiseSet3(boolean rise) { 913// 914// // Compute day number for 0.0 Jan 2000 epoch 915// double d = (double)(time - EPOCH_2000_MS) / DAY_MS; 916// 917// // Now compute the Local Sidereal Time, LST: 918// // 919// double LST = 98.9818 + 0.985647352 * d + /*UT*15 + long*/ 920// fLongitude*RAD_DEG; 921// // 922// // (east long. positive). Note that LST is here expressed in degrees, 923// // where 15 degrees corresponds to one hour. Since LST really is an angle, 924// // it's convenient to use one unit---degrees---throughout. 925// 926// // COMPUTING THE SUN'S POSITION 927// // ---------------------------- 928// // 929// // To be able to compute the Sun's rise/set times, you need to be able to 930// // compute the Sun's position at any time. First compute the "day 931// // number" d as outlined above, for the desired moment. Next compute: 932// // 933// double oblecl = 23.4393 - 3.563E-7 * d; 934// // 935// double w = 282.9404 + 4.70935E-5 * d; 936// double M = 356.0470 + 0.9856002585 * d; 937// double e = 0.016709 - 1.151E-9 * d; 938// // 939// // This is the obliquity of the ecliptic, plus some of the elements of 940// // the Sun's apparent orbit (i.e., really the Earth's orbit): w = 941// // argument of perihelion, M = mean anomaly, e = eccentricity. 942// // Semi-major axis is here assumed to be exactly 1.0 (while not strictly 943// // true, this is still an accurate approximation). Next compute E, the 944// // eccentric anomaly: 945// // 946// double E = M + e*(180/PI) * ::sin(M*DEG_RAD) * ( 1.0 + e*cos(M*DEG_RAD) ); 947// // 948// // where E and M are in degrees. This is it---no further iterations are 949// // needed because we know e has a sufficiently small value. Next compute 950// // the true anomaly, v, and the distance, r: 951// // 952// /* r * cos(v) = */ double A = cos(E*DEG_RAD) - e; 953// /* r * ::sin(v) = */ double B = ::sqrt(1 - e*e) * ::sin(E*DEG_RAD); 954// // 955// // and 956// // 957// // r = sqrt( A*A + B*B ) 958// double v = ::atan2( B, A )*RAD_DEG; 959// // 960// // The Sun's true longitude, slon, can now be computed: 961// // 962// double slon = v + w; 963// // 964// // Since the Sun is always at the ecliptic (or at least very very close to 965// // it), we can use simplified formulae to convert slon (the Sun's ecliptic 966// // longitude) to sRA and sDec (the Sun's RA and Dec): 967// // 968// // ::sin(slon) * cos(oblecl) 969// // tan(sRA) = ------------------------- 970// // cos(slon) 971// // 972// // ::sin(sDec) = ::sin(oblecl) * ::sin(slon) 973// // 974// // As was the case when computing az, the Azimuth, if possible use an 975// // atan2() function to compute sRA. 976// 977// double sRA = ::atan2(sin(slon*DEG_RAD) * cos(oblecl*DEG_RAD), cos(slon*DEG_RAD))*RAD_DEG; 978// 979// double sin_sDec = ::sin(oblecl*DEG_RAD) * ::sin(slon*DEG_RAD); 980// double sDec = ::asin(sin_sDec)*RAD_DEG; 981// 982// // COMPUTING RISE AND SET TIMES 983// // ---------------------------- 984// // 985// // To compute when an object rises or sets, you must compute when it 986// // passes the meridian and the HA of rise/set. Then the rise time is 987// // the meridian time minus HA for rise/set, and the set time is the 988// // meridian time plus the HA for rise/set. 989// // 990// // To find the meridian time, compute the Local Sidereal Time at 0h local 991// // time (or 0h UT if you prefer to work in UT) as outlined above---name 992// // that quantity LST0. The Meridian Time, MT, will now be: 993// // 994// // MT = RA - LST0 995// double MT = normalize(sRA - LST, 360); 996// // 997// // where "RA" is the object's Right Ascension (in degrees!). If negative, 998// // add 360 deg to MT. If the object is the Sun, leave the time as it is, 999// // but if it's stellar, multiply MT by 365.2422/366.2422, to convert from 1000// // sidereal to solar time. Now, compute HA for rise/set, name that 1001// // quantity HA0: 1002// // 1003// // ::sin(h0) - ::sin(lat) * ::sin(Dec) 1004// // cos(HA0) = --------------------------------- 1005// // cos(lat) * cos(Dec) 1006// // 1007// // where h0 is the altitude selected to represent rise/set. For a purely 1008// // mathematical horizon, set h0 = 0 and simplify to: 1009// // 1010// // cos(HA0) = - tan(lat) * tan(Dec) 1011// // 1012// // If you want to account for refraction on the atmosphere, set h0 = -35/60 1013// // degrees (-35 arc minutes), and if you want to compute the rise/set times 1014// // for the Sun's upper limb, set h0 = -50/60 (-50 arc minutes). 1015// // 1016// double h0 = -50/60 * DEG_RAD; 1017// 1018// double HA0 = ::acos( 1019// (sin(h0) - ::sin(fLatitude) * sin_sDec) / 1020// (cos(fLatitude) * cos(sDec*DEG_RAD)))*RAD_DEG; 1021// 1022// // When HA0 has been computed, leave it as it is for the Sun but multiply 1023// // by 365.2422/366.2422 for stellar objects, to convert from sidereal to 1024// // solar time. Finally compute: 1025// // 1026// // Rise time = MT - HA0 1027// // Set time = MT + HA0 1028// // 1029// // convert the times from degrees to hours by dividing by 15. 1030// // 1031// // If you'd like to check that your calculations are accurate or just 1032// // need a quick result, check the USNO's Sun or Moon Rise/Set Table, 1033// // <URL:http://aa.usno.navy.mil/AA/data/docs/RS_OneYear.html>. 1034// 1035// double result = MT + (rise ? -HA0 : HA0); // in degrees 1036// 1037// // Find UT midnight on this day 1038// long midnight = DAY_MS * (time / DAY_MS); 1039// 1040// return midnight + (long) (result * 3600000 / 15); 1041// } 1042 1043//------------------------------------------------------------------------- 1044// The Moon 1045//------------------------------------------------------------------------- 1046 1047#define moonL0 (318.351648 * CalendarAstronomer::PI/180 ) // Mean long. at epoch 1048#define moonP0 ( 36.340410 * CalendarAstronomer::PI/180 ) // Mean long. of perigee 1049#define moonN0 ( 318.510107 * CalendarAstronomer::PI/180 ) // Mean long. of node 1050#define moonI ( 5.145366 * CalendarAstronomer::PI/180 ) // Inclination of orbit 1051#define moonE ( 0.054900 ) // Eccentricity of orbit 1052 1053// These aren't used right now 1054#define moonA ( 3.84401e5 ) // semi-major axis (km) 1055#define moonT0 ( 0.5181 * CalendarAstronomer::PI/180 ) // Angular size at distance A 1056#define moonPi ( 0.9507 * CalendarAstronomer::PI/180 ) // Parallax at distance A 1057 1058/** 1059 * The position of the moon at the time set on this 1060 * object, in equatorial coordinates. 1061 * @internal 1062 * @deprecated ICU 2.4. This class may be removed or modified. 1063 */ 1064const CalendarAstronomer::Equatorial& CalendarAstronomer::getMoonPosition() 1065{ 1066 // 1067 // See page 142 of "Practial Astronomy with your Calculator", 1068 // by Peter Duffet-Smith, for details on the algorithm. 1069 // 1070 if (moonPositionSet == FALSE) { 1071 // Calculate the solar longitude. Has the side effect of 1072 // filling in "meanAnomalySun" as well. 1073 getSunLongitude(); 1074 1075 // 1076 // Find the # of days since the epoch of our orbital parameters. 1077 // TODO: Convert the time of day portion into ephemeris time 1078 // 1079 double day = getJulianDay() - JD_EPOCH; // Days since epoch 1080 1081 // Calculate the mean longitude and anomaly of the moon, based on 1082 // a circular orbit. Similar to the corresponding solar calculation. 1083 double meanLongitude = norm2PI(13.1763966*PI/180*day + moonL0); 1084 meanAnomalyMoon = norm2PI(meanLongitude - 0.1114041*PI/180 * day - moonP0); 1085 1086 // 1087 // Calculate the following corrections: 1088 // Evection: the sun's gravity affects the moon's eccentricity 1089 // Annual Eqn: variation in the effect due to earth-sun distance 1090 // A3: correction factor (for ???) 1091 // 1092 double evection = 1.2739*PI/180 * ::sin(2 * (meanLongitude - sunLongitude) 1093 - meanAnomalyMoon); 1094 double annual = 0.1858*PI/180 * ::sin(meanAnomalySun); 1095 double a3 = 0.3700*PI/180 * ::sin(meanAnomalySun); 1096 1097 meanAnomalyMoon += evection - annual - a3; 1098 1099 // 1100 // More correction factors: 1101 // center equation of the center correction 1102 // a4 yet another error correction (???) 1103 // 1104 // TODO: Skip the equation of the center correction and solve Kepler's eqn? 1105 // 1106 double center = 6.2886*PI/180 * ::sin(meanAnomalyMoon); 1107 double a4 = 0.2140*PI/180 * ::sin(2 * meanAnomalyMoon); 1108 1109 // Now find the moon's corrected longitude 1110 moonLongitude = meanLongitude + evection + center - annual + a4; 1111 1112 // 1113 // And finally, find the variation, caused by the fact that the sun's 1114 // gravitational pull on the moon varies depending on which side of 1115 // the earth the moon is on 1116 // 1117 double variation = 0.6583*CalendarAstronomer::PI/180 * ::sin(2*(moonLongitude - sunLongitude)); 1118 1119 moonLongitude += variation; 1120 1121 // 1122 // What we've calculated so far is the moon's longitude in the plane 1123 // of its own orbit. Now map to the ecliptic to get the latitude 1124 // and longitude. First we need to find the longitude of the ascending 1125 // node, the position on the ecliptic where it is crossed by the moon's 1126 // orbit as it crosses from the southern to the northern hemisphere. 1127 // 1128 double nodeLongitude = norm2PI(moonN0 - 0.0529539*PI/180 * day); 1129 1130 nodeLongitude -= 0.16*PI/180 * ::sin(meanAnomalySun); 1131 1132 double y = ::sin(moonLongitude - nodeLongitude); 1133 double x = cos(moonLongitude - nodeLongitude); 1134 1135 moonEclipLong = ::atan2(y*cos(moonI), x) + nodeLongitude; 1136 double moonEclipLat = ::asin(y * ::sin(moonI)); 1137 1138 eclipticToEquatorial(moonPosition, moonEclipLong, moonEclipLat); 1139 moonPositionSet = TRUE; 1140 } 1141 return moonPosition; 1142} 1143 1144/** 1145 * The "age" of the moon at the time specified in this object. 1146 * This is really the angle between the 1147 * current ecliptic longitudes of the sun and the moon, 1148 * measured in radians. 1149 * 1150 * @see #getMoonPhase 1151 * @internal 1152 * @deprecated ICU 2.4. This class may be removed or modified. 1153 */ 1154double CalendarAstronomer::getMoonAge() { 1155 // See page 147 of "Practial Astronomy with your Calculator", 1156 // by Peter Duffet-Smith, for details on the algorithm. 1157 // 1158 // Force the moon's position to be calculated. We're going to use 1159 // some the intermediate results cached during that calculation. 1160 // 1161 getMoonPosition(); 1162 1163 return norm2PI(moonEclipLong - sunLongitude); 1164} 1165 1166/** 1167 * Calculate the phase of the moon at the time set in this object. 1168 * The returned phase is a <code>double</code> in the range 1169 * <code>0 <= phase < 1</code>, interpreted as follows: 1170 * <ul> 1171 * <li>0.00: New moon 1172 * <li>0.25: First quarter 1173 * <li>0.50: Full moon 1174 * <li>0.75: Last quarter 1175 * </ul> 1176 * 1177 * @see #getMoonAge 1178 * @internal 1179 * @deprecated ICU 2.4. This class may be removed or modified. 1180 */ 1181double CalendarAstronomer::getMoonPhase() { 1182 // See page 147 of "Practial Astronomy with your Calculator", 1183 // by Peter Duffet-Smith, for details on the algorithm. 1184 return 0.5 * (1 - cos(getMoonAge())); 1185} 1186 1187/** 1188 * Constant representing a new moon. 1189 * For use with {@link #getMoonTime getMoonTime} 1190 * @internal 1191 * @deprecated ICU 2.4. This class may be removed or modified. 1192 */ 1193const CalendarAstronomer::MoonAge CalendarAstronomer::NEW_MOON() { 1194 return CalendarAstronomer::MoonAge(0); 1195} 1196 1197/** 1198 * Constant representing the moon's first quarter. 1199 * For use with {@link #getMoonTime getMoonTime} 1200 * @internal 1201 * @deprecated ICU 2.4. This class may be removed or modified. 1202 */ 1203/*const CalendarAstronomer::MoonAge CalendarAstronomer::FIRST_QUARTER() { 1204 return CalendarAstronomer::MoonAge(CalendarAstronomer::PI/2); 1205}*/ 1206 1207/** 1208 * Constant representing a full moon. 1209 * For use with {@link #getMoonTime getMoonTime} 1210 * @internal 1211 * @deprecated ICU 2.4. This class may be removed or modified. 1212 */ 1213const CalendarAstronomer::MoonAge CalendarAstronomer::FULL_MOON() { 1214 return CalendarAstronomer::MoonAge(CalendarAstronomer::PI); 1215} 1216/** 1217 * Constant representing the moon's last quarter. 1218 * For use with {@link #getMoonTime getMoonTime} 1219 * @internal 1220 * @deprecated ICU 2.4. This class may be removed or modified. 1221 */ 1222 1223class MoonTimeAngleFunc : public CalendarAstronomer::AngleFunc { 1224public: 1225 virtual ~MoonTimeAngleFunc(); 1226 virtual double eval(CalendarAstronomer&a) { return a.getMoonAge(); } 1227}; 1228 1229MoonTimeAngleFunc::~MoonTimeAngleFunc() {} 1230 1231/*const CalendarAstronomer::MoonAge CalendarAstronomer::LAST_QUARTER() { 1232 return CalendarAstronomer::MoonAge((CalendarAstronomer::PI*3)/2); 1233}*/ 1234 1235/** 1236 * Find the next or previous time at which the Moon's ecliptic 1237 * longitude will have the desired value. 1238 * <p> 1239 * @param desired The desired longitude. 1240 * @param next <tt>true</tt> if the next occurrance of the phase 1241 * is desired, <tt>false</tt> for the previous occurrance. 1242 * @internal 1243 * @deprecated ICU 2.4. This class may be removed or modified. 1244 */ 1245UDate CalendarAstronomer::getMoonTime(double desired, UBool next) 1246{ 1247 MoonTimeAngleFunc func; 1248 return timeOfAngle( func, 1249 desired, 1250 SYNODIC_MONTH, 1251 MINUTE_MS, 1252 next); 1253} 1254 1255/** 1256 * Find the next or previous time at which the moon will be in the 1257 * desired phase. 1258 * <p> 1259 * @param desired The desired phase of the moon. 1260 * @param next <tt>true</tt> if the next occurrance of the phase 1261 * is desired, <tt>false</tt> for the previous occurrance. 1262 * @internal 1263 * @deprecated ICU 2.4. This class may be removed or modified. 1264 */ 1265UDate CalendarAstronomer::getMoonTime(const CalendarAstronomer::MoonAge& desired, UBool next) { 1266 return getMoonTime(desired.value, next); 1267} 1268 1269class MoonRiseSetCoordFunc : public CalendarAstronomer::CoordFunc { 1270public: 1271 virtual ~MoonRiseSetCoordFunc(); 1272 virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { result = a.getMoonPosition(); } 1273}; 1274 1275MoonRiseSetCoordFunc::~MoonRiseSetCoordFunc() {} 1276 1277/** 1278 * Returns the time (GMT) of sunrise or sunset on the local date to which 1279 * this calendar is currently set. 1280 * @internal 1281 * @deprecated ICU 2.4. This class may be removed or modified. 1282 */ 1283UDate CalendarAstronomer::getMoonRiseSet(UBool rise) 1284{ 1285 MoonRiseSetCoordFunc func; 1286 return riseOrSet(func, 1287 rise, 1288 .533 * DEG_RAD, // Angular Diameter 1289 34 /60.0 * DEG_RAD, // Refraction correction 1290 MINUTE_MS); // Desired accuracy 1291} 1292 1293//------------------------------------------------------------------------- 1294// Interpolation methods for finding the time at which a given event occurs 1295//------------------------------------------------------------------------- 1296 1297UDate CalendarAstronomer::timeOfAngle(AngleFunc& func, double desired, 1298 double periodDays, double epsilon, UBool next) 1299{ 1300 // Find the value of the function at the current time 1301 double lastAngle = func.eval(*this); 1302 1303 // Find out how far we are from the desired angle 1304 double deltaAngle = norm2PI(desired - lastAngle) ; 1305 1306 // Using the average period, estimate the next (or previous) time at 1307 // which the desired angle occurs. 1308 double deltaT = (deltaAngle + (next ? 0.0 : - CalendarAstronomer_PI2 )) * (periodDays*DAY_MS) / CalendarAstronomer_PI2; 1309 1310 double lastDeltaT = deltaT; // Liu 1311 UDate startTime = fTime; // Liu 1312 1313 setTime(fTime + uprv_ceil(deltaT)); 1314 1315 // Now iterate until we get the error below epsilon. Throughout 1316 // this loop we use normPI to get values in the range -Pi to Pi, 1317 // since we're using them as correction factors rather than absolute angles. 1318 do { 1319 // Evaluate the function at the time we've estimated 1320 double angle = func.eval(*this); 1321 1322 // Find the # of milliseconds per radian at this point on the curve 1323 double factor = uprv_fabs(deltaT / normPI(angle-lastAngle)); 1324 1325 // Correct the time estimate based on how far off the angle is 1326 deltaT = normPI(desired - angle) * factor; 1327 1328 // HACK: 1329 // 1330 // If abs(deltaT) begins to diverge we need to quit this loop. 1331 // This only appears to happen when attempting to locate, for 1332 // example, a new moon on the day of the new moon. E.g.: 1333 // 1334 // This result is correct: 1335 // newMoon(7508(Mon Jul 23 00:00:00 CST 1990,false))= 1336 // Sun Jul 22 10:57:41 CST 1990 1337 // 1338 // But attempting to make the same call a day earlier causes deltaT 1339 // to diverge: 1340 // CalendarAstronomer.timeOfAngle() diverging: 1.348508727575625E9 -> 1341 // 1.3649828540224032E9 1342 // newMoon(7507(Sun Jul 22 00:00:00 CST 1990,false))= 1343 // Sun Jul 08 13:56:15 CST 1990 1344 // 1345 // As a temporary solution, we catch this specific condition and 1346 // adjust our start time by one eighth period days (either forward 1347 // or backward) and try again. 1348 // Liu 11/9/00 1349 if (uprv_fabs(deltaT) > uprv_fabs(lastDeltaT)) { 1350 double delta = uprv_ceil (periodDays * DAY_MS / 8.0); 1351 setTime(startTime + (next ? delta : -delta)); 1352 return timeOfAngle(func, desired, periodDays, epsilon, next); 1353 } 1354 1355 lastDeltaT = deltaT; 1356 lastAngle = angle; 1357 1358 setTime(fTime + uprv_ceil(deltaT)); 1359 } 1360 while (uprv_fabs(deltaT) > epsilon); 1361 1362 return fTime; 1363} 1364 1365UDate CalendarAstronomer::riseOrSet(CoordFunc& func, UBool rise, 1366 double diameter, double refraction, 1367 double epsilon) 1368{ 1369 Equatorial pos; 1370 double tanL = ::tan(fLatitude); 1371 double deltaT = 0; 1372 int32_t count = 0; 1373 1374 // 1375 // Calculate the object's position at the current time, then use that 1376 // position to calculate the time of rising or setting. The position 1377 // will be different at that time, so iterate until the error is allowable. 1378 // 1379 U_DEBUG_ASTRO_MSG(("setup rise=%s, dia=%.3lf, ref=%.3lf, eps=%.3lf\n", 1380 rise?"T":"F", diameter, refraction, epsilon)); 1381 do { 1382 // See "Practical Astronomy With Your Calculator, section 33. 1383 func.eval(pos, *this); 1384 double angle = ::acos(-tanL * ::tan(pos.declination)); 1385 double lst = ((rise ? CalendarAstronomer_PI2-angle : angle) + pos.ascension ) * 24 / CalendarAstronomer_PI2; 1386 1387 // Convert from LST to Universal Time. 1388 UDate newTime = lstToUT( lst ); 1389 1390 deltaT = newTime - fTime; 1391 setTime(newTime); 1392 U_DEBUG_ASTRO_MSG(("%d] dT=%.3lf, angle=%.3lf, lst=%.3lf, A=%.3lf/D=%.3lf\n", 1393 count, deltaT, angle, lst, pos.ascension, pos.declination)); 1394 } 1395 while (++ count < 5 && uprv_fabs(deltaT) > epsilon); 1396 1397 // Calculate the correction due to refraction and the object's angular diameter 1398 double cosD = ::cos(pos.declination); 1399 double psi = ::acos(sin(fLatitude) / cosD); 1400 double x = diameter / 2 + refraction; 1401 double y = ::asin(sin(x) / ::sin(psi)); 1402 long delta = (long)((240 * y * RAD_DEG / cosD)*SECOND_MS); 1403 1404 return fTime + (rise ? -delta : delta); 1405} 1406 /** 1407 * Return the obliquity of the ecliptic (the angle between the ecliptic 1408 * and the earth's equator) at the current time. This varies due to 1409 * the precession of the earth's axis. 1410 * 1411 * @return the obliquity of the ecliptic relative to the equator, 1412 * measured in radians. 1413 */ 1414double CalendarAstronomer::eclipticObliquity() { 1415 if (isINVALID(eclipObliquity)) { 1416 const double epoch = 2451545.0; // 2000 AD, January 1.5 1417 1418 double T = (getJulianDay() - epoch) / 36525; 1419 1420 eclipObliquity = 23.439292 1421 - 46.815/3600 * T 1422 - 0.0006/3600 * T*T 1423 + 0.00181/3600 * T*T*T; 1424 1425 eclipObliquity *= DEG_RAD; 1426 } 1427 return eclipObliquity; 1428} 1429 1430 1431//------------------------------------------------------------------------- 1432// Private data 1433//------------------------------------------------------------------------- 1434void CalendarAstronomer::clearCache() { 1435 const double INVALID = uprv_getNaN(); 1436 1437 julianDay = INVALID; 1438 julianCentury = INVALID; 1439 sunLongitude = INVALID; 1440 meanAnomalySun = INVALID; 1441 moonLongitude = INVALID; 1442 moonEclipLong = INVALID; 1443 meanAnomalyMoon = INVALID; 1444 eclipObliquity = INVALID; 1445 siderealTime = INVALID; 1446 siderealT0 = INVALID; 1447 moonPositionSet = FALSE; 1448} 1449 1450//private static void out(String s) { 1451// System.out.println(s); 1452//} 1453 1454//private static String deg(double rad) { 1455// return Double.toString(rad * RAD_DEG); 1456//} 1457 1458//private static String hours(long ms) { 1459// return Double.toString((double)ms / HOUR_MS) + " hours"; 1460//} 1461 1462/** 1463 * @internal 1464 * @deprecated ICU 2.4. This class may be removed or modified. 1465 */ 1466/*UDate CalendarAstronomer::local(UDate localMillis) { 1467 // TODO - srl ? 1468 TimeZone *tz = TimeZone::createDefault(); 1469 int32_t rawOffset; 1470 int32_t dstOffset; 1471 UErrorCode status = U_ZERO_ERROR; 1472 tz->getOffset(localMillis, TRUE, rawOffset, dstOffset, status); 1473 delete tz; 1474 return localMillis - rawOffset; 1475}*/ 1476 1477// Debugging functions 1478UnicodeString CalendarAstronomer::Ecliptic::toString() const 1479{ 1480#ifdef U_DEBUG_ASTRO 1481 char tmp[800]; 1482 sprintf(tmp, "[%.5f,%.5f]", longitude*RAD_DEG, latitude*RAD_DEG); 1483 return UnicodeString(tmp, ""); 1484#else 1485 return UnicodeString(); 1486#endif 1487} 1488 1489UnicodeString CalendarAstronomer::Equatorial::toString() const 1490{ 1491#ifdef U_DEBUG_ASTRO 1492 char tmp[400]; 1493 sprintf(tmp, "%f,%f", 1494 (ascension*RAD_DEG), (declination*RAD_DEG)); 1495 return UnicodeString(tmp, ""); 1496#else 1497 return UnicodeString(); 1498#endif 1499} 1500 1501UnicodeString CalendarAstronomer::Horizon::toString() const 1502{ 1503#ifdef U_DEBUG_ASTRO 1504 char tmp[800]; 1505 sprintf(tmp, "[%.5f,%.5f]", altitude*RAD_DEG, azimuth*RAD_DEG); 1506 return UnicodeString(tmp, ""); 1507#else 1508 return UnicodeString(); 1509#endif 1510} 1511 1512 1513// static private String radToHms(double angle) { 1514// int hrs = (int) (angle*RAD_HOUR); 1515// int min = (int)((angle*RAD_HOUR - hrs) * 60); 1516// int sec = (int)((angle*RAD_HOUR - hrs - min/60.0) * 3600); 1517 1518// return Integer.toString(hrs) + "h" + min + "m" + sec + "s"; 1519// } 1520 1521// static private String radToDms(double angle) { 1522// int deg = (int) (angle*RAD_DEG); 1523// int min = (int)((angle*RAD_DEG - deg) * 60); 1524// int sec = (int)((angle*RAD_DEG - deg - min/60.0) * 3600); 1525 1526// return Integer.toString(deg) + "\u00b0" + min + "'" + sec + "\""; 1527// } 1528 1529// =============== Calendar Cache ================ 1530 1531void CalendarCache::createCache(CalendarCache** cache, UErrorCode& status) { 1532 ucln_i18n_registerCleanup(UCLN_I18N_ASTRO_CALENDAR, calendar_astro_cleanup); 1533 if(cache == NULL) { 1534 status = U_MEMORY_ALLOCATION_ERROR; 1535 } else { 1536 *cache = new CalendarCache(32, status); 1537 if(U_FAILURE(status)) { 1538 delete *cache; 1539 *cache = NULL; 1540 } 1541 } 1542} 1543 1544int32_t CalendarCache::get(CalendarCache** cache, int32_t key, UErrorCode &status) { 1545 int32_t res; 1546 1547 if(U_FAILURE(status)) { 1548 return 0; 1549 } 1550 umtx_lock(&ccLock); 1551 1552 if(*cache == NULL) { 1553 createCache(cache, status); 1554 if(U_FAILURE(status)) { 1555 umtx_unlock(&ccLock); 1556 return 0; 1557 } 1558 } 1559 1560 res = uhash_igeti((*cache)->fTable, key); 1561 U_DEBUG_ASTRO_MSG(("%p: GET: [%d] == %d\n", (*cache)->fTable, key, res)); 1562 1563 umtx_unlock(&ccLock); 1564 return res; 1565} 1566 1567void CalendarCache::put(CalendarCache** cache, int32_t key, int32_t value, UErrorCode &status) { 1568 if(U_FAILURE(status)) { 1569 return; 1570 } 1571 umtx_lock(&ccLock); 1572 1573 if(*cache == NULL) { 1574 createCache(cache, status); 1575 if(U_FAILURE(status)) { 1576 umtx_unlock(&ccLock); 1577 return; 1578 } 1579 } 1580 1581 uhash_iputi((*cache)->fTable, key, value, &status); 1582 U_DEBUG_ASTRO_MSG(("%p: PUT: [%d] := %d\n", (*cache)->fTable, key, value)); 1583 1584 umtx_unlock(&ccLock); 1585} 1586 1587CalendarCache::CalendarCache(int32_t size, UErrorCode &status) { 1588 fTable = uhash_openSize(uhash_hashLong, uhash_compareLong, NULL, size, &status); 1589 U_DEBUG_ASTRO_MSG(("%p: Opening.\n", fTable)); 1590} 1591 1592CalendarCache::~CalendarCache() { 1593 if(fTable != NULL) { 1594 U_DEBUG_ASTRO_MSG(("%p: Closing.\n", fTable)); 1595 uhash_close(fTable); 1596 } 1597} 1598 1599U_NAMESPACE_END 1600 1601#endif // !UCONFIG_NO_FORMATTING 1602