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 29 static void debug_astro_loc(const char *f, int32_t l) 30 { 31 fprintf(stderr, "%s:%d: ", f, l); 32 } 33 34 static 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" 43 static 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 62 static inline UBool isINVALID(double d) { 63 return(uprv_isNaN(d)); 64 } 65 66 static UMutex ccLock = U_MUTEX_INITIALIZER; 67 68 U_CDECL_BEGIN 69 static UBool calendar_astro_cleanup(void) { 70 return TRUE; 71 } 72 U_CDECL_END 73 74 U_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 */ 103 const 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 201 const 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 */ 212 inline 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 */ 221 inline 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 */ 228 inline 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 */ 242 CalendarAstronomer::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 */ 253 CalendarAstronomer::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 */ 272 CalendarAstronomer::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 } 279 280 CalendarAstronomer::~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 */ 300 void 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 */ 321 void 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 */ 337 UDate 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 */ 351 double 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 */ 366 double 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 */ 378 double 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 } 389 390 double 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 */ 405 double 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 */ 418 double 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 */ 444 CalendarAstronomer::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 */ 459 CalendarAstronomer::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 */ 489 CalendarAstronomer::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 */ 498 CalendarAstronomer::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 */ 594 static 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 */ 622 double 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 */ 664 CalendarAstronomer::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 */ 687 double 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 */ 709 double CalendarAstronomer::WINTER_SOLSTICE() { 710 return ((CalendarAstronomer::PI*3)/2); 711 } 712 713 CalendarAstronomer::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 */ 721 class SunTimeAngleFunc : public CalendarAstronomer::AngleFunc { 722 public: 723 virtual ~SunTimeAngleFunc(); 724 virtual double eval(CalendarAstronomer& a) { return a.getSunLongitude(); } 725 }; 726 727 SunTimeAngleFunc::~SunTimeAngleFunc() {} 728 729 UDate 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 } 738 739 CalendarAstronomer::CoordFunc::~CoordFunc() {} 740 741 class RiseSetCoordFunc : public CalendarAstronomer::CoordFunc { 742 public: 743 virtual ~RiseSetCoordFunc(); 744 virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { a.getSunPosition(result); } 745 }; 746 747 RiseSetCoordFunc::~RiseSetCoordFunc() {} 748 749 UDate 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 */ 1064 const 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 */ 1154 double 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 */ 1181 double 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 */ 1193 const 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 */ 1213 const 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 1223 class MoonTimeAngleFunc : public CalendarAstronomer::AngleFunc { 1224 public: 1225 virtual ~MoonTimeAngleFunc(); 1226 virtual double eval(CalendarAstronomer&a) { return a.getMoonAge(); } 1227 }; 1228 1229 MoonTimeAngleFunc::~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 */ 1245 UDate 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 */ 1265 UDate CalendarAstronomer::getMoonTime(const CalendarAstronomer::MoonAge& desired, UBool next) { 1266 return getMoonTime(desired.value, next); 1267 } 1268 1269 class MoonRiseSetCoordFunc : public CalendarAstronomer::CoordFunc { 1270 public: 1271 virtual ~MoonRiseSetCoordFunc(); 1272 virtual void eval(CalendarAstronomer::Equatorial& result, CalendarAstronomer&a) { result = a.getMoonPosition(); } 1273 }; 1274 1275 MoonRiseSetCoordFunc::~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 */ 1283 UDate 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 1297 UDate 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 1365 UDate 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 */ 1414 double 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 //------------------------------------------------------------------------- 1434 void 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 1478 UnicodeString 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 1489 UnicodeString 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 1501 UnicodeString 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 1531 void 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 1544 int32_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 1567 void 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 1587 CalendarCache::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 1592 CalendarCache::~CalendarCache() { 1593 if(fTable != NULL) { 1594 U_DEBUG_ASTRO_MSG(("%p: Closing.\n", fTable)); 1595 uhash_close(fTable); 1596 } 1597 } 1598 1599 U_NAMESPACE_END 1600 1601 #endif // !UCONFIG_NO_FORMATTING 1602
