CalendarAstronomer is a class that can perform the calculations to
- * determine the positions of the sun and moon, the time of sunrise and
- * sunset, and other astronomy-related data. The calculations it performs
- * are in some cases quite complicated, and this utility class saves you
- * the trouble of worrying about them.
- *
- * The measurement of time is a very important part of astronomy. Because
- * astronomical bodies are constantly in motion, observations are only valid
- * at a given moment in time. Accordingly, each CalendarAstronomer
- * object has a time property that determines the date
- * and time for which its calculations are performed. You can set and
- * retrieve this property with {@link #setDate setDate}, {@link #getDate getDate}
- * and related methods.
- *
- * Almost all of the calculations performed by this class, or by any - * astronomer, are approximations to various degrees of accuracy. The - * calculations in this class are mostly modelled after those described - * in the book - * - * Practical Astronomy With Your Calculator, by Peter J. - * Duffett-Smith, Cambridge University Press, 1990. This is an excellent - * book, and if you want a greater understanding of how these calculations - * are performed it a very good, readable starting point. - *
- * WARNING: This class is very early in its development, and
- * it is highly likely that its API will change to some degree in the future.
- * At the moment, it basically does just enough to support {@link com.ibm.icu.util.IslamicCalendar}
- * and {@link com.ibm.icu.util.ChineseCalendar}.
- *
- * @author Laura Werner
- * @author Alan Liu
- * @internal
- */
-public class CalendarAstronomer {
-
- //-------------------------------------------------------------------------
- // Astronomical constants
- //-------------------------------------------------------------------------
-
- /**
- * The number of standard hours in one sidereal day.
- * Approximately 24.93.
- * @internal
- */
- public static final double SIDEREAL_DAY = 23.93446960027;
-
- /**
- * The number of sidereal hours in one mean solar day.
- * Approximately 24.07.
- * @internal
- */
- public static final double SOLAR_DAY = 24.065709816;
-
- /**
- * The average number of solar days from one new moon to the next. This is the time
- * it takes for the moon to return the same ecliptic longitude as the sun.
- * It is longer than the sidereal month because the sun's longitude increases
- * during the year due to the revolution of the earth around the sun.
- * Approximately 29.53.
- *
- * @see #SIDEREAL_MONTH
- * @internal
- */
- public static final double SYNODIC_MONTH = 29.530588853;
-
- /**
- * The average number of days it takes
- * for the moon to return to the same ecliptic longitude relative to the
- * stellar background. This is referred to as the sidereal month.
- * It is shorter than the synodic month due to
- * the revolution of the earth around the sun.
- * Approximately 27.32.
- *
- * @see #SYNODIC_MONTH
- * @internal
- */
- public static final double SIDEREAL_MONTH = 27.32166;
-
- /**
- * The average number number of days between successive vernal equinoxes.
- * Due to the precession of the earth's
- * axis, this is not precisely the same as the sidereal year.
- * Approximately 365.24
- *
- * @see #SIDEREAL_YEAR
- * @internal
- */
- public static final double TROPICAL_YEAR = 365.242191;
-
- /**
- * The average number of days it takes
- * for the sun to return to the same position against the fixed stellar
- * background. This is the duration of one orbit of the earth about the sun
- * as it would appear to an outside observer.
- * Due to the precession of the earth's
- * axis, this is not precisely the same as the tropical year.
- * Approximately 365.25.
- *
- * @see #TROPICAL_YEAR
- * @internal
- */
- public static final double SIDEREAL_YEAR = 365.25636;
-
- //-------------------------------------------------------------------------
- // Time-related constants
- //-------------------------------------------------------------------------
-
- /**
- * The number of milliseconds in one second.
- * @internal
- */
- public static final int SECOND_MS = 1000;
-
- /**
- * The number of milliseconds in one minute.
- * @internal
- */
- public static final int MINUTE_MS = 60*SECOND_MS;
-
- /**
- * The number of milliseconds in one hour.
- * @internal
- */
- public static final int HOUR_MS = 60*MINUTE_MS;
-
- /**
- * The number of milliseconds in one day.
- * @internal
- */
- public static final long DAY_MS = 24*HOUR_MS;
-
- /**
- * The start of the julian day numbering scheme used by astronomers, which
- * is 1/1/4713 BC (Julian), 12:00 GMT. This is given as the number of milliseconds
- * since 1/1/1970 AD (Gregorian), a negative number.
- * Note that julian day numbers and
- * the Julian calendar are not the same thing. Also note that
- * julian days start at noon, not midnight.
- * @internal
- */
- public static final long JULIAN_EPOCH_MS = -210866760000000L;
-
-// static {
-// Calendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
-// cal.clear();
-// cal.set(cal.ERA, 0);
-// cal.set(cal.YEAR, 4713);
-// cal.set(cal.MONTH, cal.JANUARY);
-// cal.set(cal.DATE, 1);
-// cal.set(cal.HOUR_OF_DAY, 12);
-// System.out.println("1.5 Jan 4713 BC = " + cal.getTime().getTime());
-
-// cal.clear();
-// cal.set(cal.YEAR, 2000);
-// cal.set(cal.MONTH, cal.JANUARY);
-// cal.set(cal.DATE, 1);
-// cal.add(cal.DATE, -1);
-// System.out.println("0.0 Jan 2000 = " + cal.getTime().getTime());
-// }
-
- /**
- * Milliseconds value for 0.0 January 2000 AD.
- */
- static final long EPOCH_2000_MS = 946598400000L;
-
- //-------------------------------------------------------------------------
- // Assorted private data used for conversions
- //-------------------------------------------------------------------------
-
- // My own copies of these so compilers are more likely to optimize them away
- static private final double PI = 3.14159265358979323846;
- static private final double PI2 = PI * 2.0;
-
- static private final double RAD_HOUR = 12 / PI; // radians -> hours
- static private final double DEG_RAD = PI / 180; // degrees -> radians
- static private final double RAD_DEG = 180 / PI; // radians -> degrees
-
- //-------------------------------------------------------------------------
- // Constructors
- //-------------------------------------------------------------------------
-
- /**
- * Construct a new CalendarAstronomer object that is initialized to
- * the current date and time.
- * @internal
- */
- public CalendarAstronomer() {
- this(System.currentTimeMillis());
- }
-
- /**
- * Construct a new CalendarAstronomer object that is initialized to
- * the specified date and time.
- * @internal
- */
- public CalendarAstronomer(Date d) {
- this(d.getTime());
- }
-
- /**
- * Construct a new CalendarAstronomer object that is initialized to
- * the specified time. The time is expressed as a number of milliseconds since
- * January 1, 1970 AD (Gregorian).
- *
- * @see java.util.Date#getTime()
- * @internal
- */
- public CalendarAstronomer(long aTime) {
- time = aTime;
- }
-
- /**
- * Construct a new CalendarAstronomer object with the given
- * latitude and longitude. The object's time is set to the current
- * date and time.
- *
- * @param longitude The desired longitude, in degrees east of
- * the Greenwich meridian.
- *
- * @param latitude The desired latitude, in degrees. Positive
- * values signify North, negative South.
- *
- * @see java.util.Date#getTime()
- * @internal
- */
- public CalendarAstronomer(double longitude, double latitude) {
- this();
- fLongitude = normPI(longitude * DEG_RAD);
- fLatitude = normPI(latitude * DEG_RAD);
- fGmtOffset = (long)(fLongitude * 24 * HOUR_MS / PI2);
- }
-
-
- //-------------------------------------------------------------------------
- // Time and date getters and setters
- //-------------------------------------------------------------------------
-
- /**
- * Set the current date and time of this CalendarAstronomer object. All
- * astronomical calculations are performed based on this time setting.
- *
- * @param aTime the date and time, expressed as the number of milliseconds since
- * 1/1/1970 0:00 GMT (Gregorian).
- *
- * @see #setDate
- * @see #getTime
- * @internal
- */
- public void setTime(long aTime) {
- time = aTime;
- clearCache();
- }
-
- /**
- * Set the current date and time of this CalendarAstronomer object. All
- * astronomical calculations are performed based on this time setting.
- *
- * @param date the time and date, expressed as a Date object.
- *
- * @see #setTime
- * @see #getDate
- * @internal
- */
- public void setDate(Date date) {
- setTime(date.getTime());
- }
-
- /**
- * Set the current date and time of this CalendarAstronomer object. All
- * astronomical calculations are performed based on this time setting.
- *
- * @param jdn the desired time, expressed as a "julian day number",
- * which is the number of elapsed days since
- * 1/1/4713 BC (Julian), 12:00 GMT. Note that julian day
- * numbers start at noon. To get the jdn for
- * the corresponding midnight, subtract 0.5.
- *
- * @see #getJulianDay
- * @see #JULIAN_EPOCH_MS
- * @internal
- */
- public void setJulianDay(double jdn) {
- time = (long)(jdn * DAY_MS) + JULIAN_EPOCH_MS;
- clearCache();
- julianDay = jdn;
- }
-
- /**
- * Get the current time of this CalendarAstronomer object,
- * represented as the number of milliseconds since
- * 1/1/1970 AD 0:00 GMT (Gregorian).
- *
- * @see #setTime
- * @see #getDate
- * @internal
- */
- public long getTime() {
- return time;
- }
-
- /**
- * Get the current time of this CalendarAstronomer object,
- * represented as a Date object.
- *
- * @see #setDate
- * @see #getTime
- * @internal
- */
- public Date getDate() {
- return new Date(time);
- }
-
- /**
- * Get the current time of this CalendarAstronomer object,
- * expressed as a "julian day number", which is the number of elapsed
- * days since 1/1/4713 BC (Julian), 12:00 GMT.
- *
- * @see #setJulianDay
- * @see #JULIAN_EPOCH_MS
- * @internal
- */
- public double getJulianDay() {
- if (julianDay == INVALID) {
- julianDay = (double)(time - JULIAN_EPOCH_MS) / (double)DAY_MS;
- }
- return julianDay;
- }
-
- /**
- * Return this object's time expressed in julian centuries:
- * the number of centuries after 1/1/1900 AD, 12:00 GMT
- *
- * @see #getJulianDay
- * @internal
- */
- public double getJulianCentury() {
- if (julianCentury == INVALID) {
- julianCentury = (getJulianDay() - 2415020.0) / 36525;
- }
- return julianCentury;
- }
-
- /**
- * Returns the current Greenwich sidereal time, measured in hours
- * @internal
- */
- public double getGreenwichSidereal() {
- if (siderealTime == INVALID) {
- // See page 86 of "Practial Astronomy with your Calculator",
- // by Peter Duffet-Smith, for details on the algorithm.
-
- double UT = normalize((double)time/HOUR_MS, 24);
-
- siderealTime = normalize(getSiderealOffset() + UT*1.002737909, 24);
- }
- return siderealTime;
- }
-
- private double getSiderealOffset() {
- if (siderealT0 == INVALID) {
- double JD = Math.floor(getJulianDay() - 0.5) + 0.5;
- double S = JD - 2451545.0;
- double T = S / 36525.0;
- siderealT0 = normalize(6.697374558 + 2400.051336*T + 0.000025862*T*T, 24);
- }
- return siderealT0;
- }
-
- /**
- * Returns the current local sidereal time, measured in hours
- * @internal
- */
- public double getLocalSidereal() {
- return normalize(getGreenwichSidereal() + (double)fGmtOffset/HOUR_MS, 24);
- }
-
- /**
- * Converts local sidereal time to Universal Time.
- *
- * @param lst The Local Sidereal Time, in hours since sidereal midnight
- * on this object's current date.
- *
- * @return The corresponding Universal Time, in milliseconds since
- * 1 Jan 1970, GMT.
- */
- private long lstToUT(double lst) {
- // Convert to local mean time
- double lt = normalize((lst - getSiderealOffset()) * 0.9972695663, 24);
-
- // Then find local midnight on this day
- long base = DAY_MS * ((time + fGmtOffset)/DAY_MS) - fGmtOffset;
-
- //out(" lt =" + lt + " hours");
- //out(" base=" + new Date(base));
-
- return base + (long)(lt * HOUR_MS);
- }
-
-
- //-------------------------------------------------------------------------
- // Coordinate transformations, all based on the current time of this object
- //-------------------------------------------------------------------------
-
- /**
- * Convert from ecliptic to equatorial coordinates.
- *
- * @param ecliptic A point in the sky in ecliptic coordinates.
- * @return The corresponding point in equatorial coordinates.
- * @internal
- */
- public final Equatorial eclipticToEquatorial(Ecliptic ecliptic)
- {
- return eclipticToEquatorial(ecliptic.longitude, ecliptic.latitude);
- }
-
- /**
- * Convert from ecliptic to equatorial coordinates.
- *
- * @param eclipLong The ecliptic longitude
- * @param eclipLat The ecliptic latitude
- *
- * @return The corresponding point in equatorial coordinates.
- * @internal
- */
- public final Equatorial eclipticToEquatorial(double eclipLong, double eclipLat)
- {
- // See page 42 of "Practial Astronomy with your Calculator",
- // by Peter Duffet-Smith, for details on the algorithm.
-
- double obliq = eclipticObliquity();
- double sinE = Math.sin(obliq);
- double cosE = Math.cos(obliq);
-
- double sinL = Math.sin(eclipLong);
- double cosL = Math.cos(eclipLong);
-
- double sinB = Math.sin(eclipLat);
- double cosB = Math.cos(eclipLat);
- double tanB = Math.tan(eclipLat);
-
- return new Equatorial(Math.atan2(sinL*cosE - tanB*sinE, cosL),
- Math.asin(sinB*cosE + cosB*sinE*sinL) );
- }
-
- /**
- * Convert from ecliptic longitude to equatorial coordinates.
- *
- * @param eclipLong The ecliptic longitude
- *
- * @return The corresponding point in equatorial coordinates.
- * @internal
- */
- public final Equatorial eclipticToEquatorial(double eclipLong)
- {
- return eclipticToEquatorial(eclipLong, 0); // TODO: optimize
- }
-
- /**
- * @internal
- */
- public Horizon eclipticToHorizon(double eclipLong)
- {
- Equatorial equatorial = eclipticToEquatorial(eclipLong);
-
- double H = getLocalSidereal()*PI/12 - equatorial.ascension; // Hour-angle
-
- double sinH = Math.sin(H);
- double cosH = Math.cos(H);
- double sinD = Math.sin(equatorial.declination);
- double cosD = Math.cos(equatorial.declination);
- double sinL = Math.sin(fLatitude);
- double cosL = Math.cos(fLatitude);
-
- double altitude = Math.asin(sinD*sinL + cosD*cosL*cosH);
- double azimuth = Math.atan2(-cosD*cosL*sinH, sinD - sinL * Math.sin(altitude));
-
- return new Horizon(azimuth, altitude);
- }
-
-
- //-------------------------------------------------------------------------
- // The Sun
- //-------------------------------------------------------------------------
-
- //
- // Parameters of the Sun's orbit as of the epoch Jan 0.0 1990
- // Angles are in radians (after multiplying by PI/180)
- //
- static final double JD_EPOCH = 2447891.5; // Julian day of epoch
-
- static final double SUN_ETA_G = 279.403303 * PI/180; // Ecliptic longitude at epoch
- static final double SUN_OMEGA_G = 282.768422 * PI/180; // Ecliptic longitude of perigee
- static final double SUN_E = 0.016713; // Eccentricity of orbit
- //double sunR0 = 1.495585e8; // Semi-major axis in KM
- //double sunTheta0 = 0.533128 * PI/180; // Angular diameter at R0
-
- // The following three methods, which compute the sun parameters
- // given above for an arbitrary epoch (whatever time the object is
- // set to), make only a small difference as compared to using the
- // above constants. E.g., Sunset times might differ by ~12
- // seconds. Furthermore, the eta-g computation is befuddled by
- // Duffet-Smith's incorrect coefficients (p.86). I've corrected
- // the first-order coefficient but the others may be off too - no
- // way of knowing without consulting another source.
-
-// /**
-// * Return the sun's ecliptic longitude at perigee for the current time.
-// * See Duffett-Smith, p. 86.
-// * @return radians
-// */
-// private double getSunOmegaG() {
-// double T = getJulianCentury();
-// return (281.2208444 + (1.719175 + 0.000452778*T)*T) * DEG_RAD;
-// }
-
-// /**
-// * Return the sun's ecliptic longitude for the current time.
-// * See Duffett-Smith, p. 86.
-// * @return radians
-// */
-// private double getSunEtaG() {
-// double T = getJulianCentury();
-// //return (279.6966778 + (36000.76892 + 0.0003025*T)*T) * DEG_RAD;
-// //
-// // The above line is from Duffett-Smith, and yields manifestly wrong
-// // results. The below constant is derived empirically to match the
-// // constant he gives for the 1990 EPOCH.
-// //
-// return (279.6966778 + (-0.3262541582718024 + 0.0003025*T)*T) * DEG_RAD;
-// }
-
-// /**
-// * Return the sun's eccentricity of orbit for the current time.
-// * See Duffett-Smith, p. 86.
-// * @return double
-// */
-// private double getSunE() {
-// double T = getJulianCentury();
-// return 0.01675104 - (0.0000418 + 0.000000126*T)*T;
-// }
-
- /**
- * The longitude of the sun at the time specified by this object.
- * The longitude is measured in radians along the ecliptic
- * from the "first point of Aries," the point at which the ecliptic
- * crosses the earth's equatorial plane at the vernal equinox.
- *
- * Currently, this method uses an approximation of the two-body Kepler's
- * equation for the earth and the sun. It does not take into account the
- * perturbations caused by the other planets, the moon, etc.
- * @internal
- */
- public double getSunLongitude()
- {
- // See page 86 of "Practial Astronomy with your Calculator",
- // by Peter Duffet-Smith, for details on the algorithm.
-
- if (sunLongitude == INVALID) {
- double[] result = getSunLongitude(getJulianDay());
- sunLongitude = result[0];
- meanAnomalySun = result[1];
- }
- return sunLongitude;
- }
-
- /**
- * TODO Make this public when the entire class is package-private.
- */
- /*public*/ double[] getSunLongitude(double julian)
- {
- // See page 86 of "Practial Astronomy with your Calculator",
- // by Peter Duffet-Smith, for details on the algorithm.
-
- double day = julian - JD_EPOCH; // Days since epoch
-
- // Find the angular distance the sun in a fictitious
- // circular orbit has travelled since the epoch.
- double epochAngle = norm2PI(PI2/TROPICAL_YEAR*day);
-
- // The epoch wasn't at the sun's perigee; find the angular distance
- // since perigee, which is called the "mean anomaly"
- double meanAnomaly = norm2PI(epochAngle + SUN_ETA_G - SUN_OMEGA_G);
-
- // Now find the "true anomaly", e.g. the real solar longitude
- // by solving Kepler's equation for an elliptical orbit
- // NOTE: The 3rd ed. of the book lists omega_g and eta_g in different
- // equations; omega_g is to be correct.
- return new double[] {
- norm2PI(trueAnomaly(meanAnomaly, SUN_E) + SUN_OMEGA_G),
- meanAnomaly
- };
- }
-
- /**
- * The position of the sun at this object's current date and time,
- * in equatorial coordinates.
- * @internal
- */
- public Equatorial getSunPosition() {
- return eclipticToEquatorial(getSunLongitude(), 0);
- }
-
- private static class SolarLongitude {
- double value;
- SolarLongitude(double val) { value = val; }
- }
-
- /**
- * Constant representing the vernal equinox.
- * For use with {@link #getSunTime(SolarLongitude, boolean) getSunTime}.
- * Note: In this case, "vernal" refers to the northern hemisphere's seasons.
- * @internal
- */
- public static final SolarLongitude VERNAL_EQUINOX = new SolarLongitude(0);
-
- /**
- * Constant representing the summer solstice.
- * For use with {@link #getSunTime(SolarLongitude, boolean) getSunTime}.
- * Note: In this case, "summer" refers to the northern hemisphere's seasons.
- * @internal
- */
- public static final SolarLongitude SUMMER_SOLSTICE = new SolarLongitude(PI/2);
-
- /**
- * Constant representing the autumnal equinox.
- * For use with {@link #getSunTime(SolarLongitude, boolean) getSunTime}.
- * Note: In this case, "autumn" refers to the northern hemisphere's seasons.
- * @internal
- */
- public static final SolarLongitude AUTUMN_EQUINOX = new SolarLongitude(PI);
-
- /**
- * Constant representing the winter solstice.
- * For use with {@link #getSunTime(SolarLongitude, boolean) getSunTime}.
- * Note: In this case, "winter" refers to the northern hemisphere's seasons.
- * @internal
- */
- public static final SolarLongitude WINTER_SOLSTICE = new SolarLongitude((PI*3)/2);
-
- /**
- * Find the next time at which the sun's ecliptic longitude will have
- * the desired value.
- * @internal
- */
- public long getSunTime(double desired, boolean next)
- {
- return timeOfAngle( new AngleFunc() { public double eval() { return getSunLongitude(); } },
- desired,
- TROPICAL_YEAR,
- MINUTE_MS,
- next);
- }
-
- /**
- * Find the next time at which the sun's ecliptic longitude will have
- * the desired value.
- * @internal
- */
- public long getSunTime(SolarLongitude desired, boolean next) {
- return getSunTime(desired.value, next);
- }
-
- /**
- * Returns the time (GMT) of sunrise or sunset on the local date to which
- * this calendar is currently set.
- *
- * NOTE: This method only works well if this object is set to a
- * time near local noon. Because of variations between the local
- * official time zone and the geographic longitude, the
- * computation can flop over into an adjacent day if this object
- * is set to a time near local midnight.
- *
- * @internal
- */
- public long getSunRiseSet(boolean rise)
- {
- long t0 = time;
-
- // Make a rough guess: 6am or 6pm local time on the current day
- long noon = ((time + fGmtOffset)/DAY_MS)*DAY_MS - fGmtOffset + 12*HOUR_MS;
-
- setTime(noon + (rise ? -6L : 6L) * HOUR_MS);
-
- long t = riseOrSet(new CoordFunc() {
- public Equatorial eval() { return getSunPosition(); }
- },
- rise,
- .533 * DEG_RAD, // Angular Diameter
- 34 /60.0 * DEG_RAD, // Refraction correction
- MINUTE_MS / 12); // Desired accuracy
-
- setTime(t0);
- return t;
- }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// //-------------------------------------------------------------------------
-// // Alternate Sun Rise/Set
-// // See Duffett-Smith p.93
-// //-------------------------------------------------------------------------
-//
-// // This yields worse results (as compared to USNO data) than getSunRiseSet().
-// /**
-// * TODO Make this public when the entire class is package-private.
-// */
-// /*public*/ long getSunRiseSet2(boolean rise) {
-// // 1. Calculate coordinates of the sun's center for midnight
-// double jd = Math.floor(getJulianDay() - 0.5) + 0.5;
-// double[] sl = getSunLongitude(jd);
-// double lambda1 = sl[0];
-// Equatorial pos1 = eclipticToEquatorial(lambda1, 0);
-//
-// // 2. Add ... to lambda to get position 24 hours later
-// double lambda2 = lambda1 + 0.985647*DEG_RAD;
-// Equatorial pos2 = eclipticToEquatorial(lambda2, 0);
-//
-// // 3. Calculate LSTs of rising and setting for these two positions
-// double tanL = Math.tan(fLatitude);
-// double H = Math.acos(-tanL * Math.tan(pos1.declination));
-// double lst1r = (PI2 + pos1.ascension - H) * 24 / PI2;
-// double lst1s = (pos1.ascension + H) * 24 / PI2;
-// H = Math.acos(-tanL * Math.tan(pos2.declination));
-// double lst2r = (PI2-H + pos2.ascension ) * 24 / PI2;
-// double lst2s = (H + pos2.ascension ) * 24 / PI2;
-// if (lst1r > 24) lst1r -= 24;
-// if (lst1s > 24) lst1s -= 24;
-// if (lst2r > 24) lst2r -= 24;
-// if (lst2s > 24) lst2s -= 24;
-//
-// // 4. Convert LSTs to GSTs. If GST1 > GST2, add 24 to GST2.
-// double gst1r = lstToGst(lst1r);
-// double gst1s = lstToGst(lst1s);
-// double gst2r = lstToGst(lst2r);
-// double gst2s = lstToGst(lst2s);
-// if (gst1r > gst2r) gst2r += 24;
-// if (gst1s > gst2s) gst2s += 24;
-//
-// // 5. Calculate GST at 0h UT of this date
-// double t00 = utToGst(0);
-//
-// // 6. Calculate GST at 0h on the observer's longitude
-// double offset = Math.round(fLongitude*12/PI); // p.95 step 6; he _rounds_ to nearest 15 deg.
-// double t00p = t00 - offset*1.002737909;
-// if (t00p < 0) t00p += 24; // do NOT normalize
-//
-// // 7. Adjust
-// if (gst1r < t00p) {
-// gst1r += 24;
-// gst2r += 24;
-// }
-// if (gst1s < t00p) {
-// gst1s += 24;
-// gst2s += 24;
-// }
-//
-// // 8.
-// double gstr = (24.07*gst1r-t00*(gst2r-gst1r))/(24.07+gst1r-gst2r);
-// double gsts = (24.07*gst1s-t00*(gst2s-gst1s))/(24.07+gst1s-gst2s);
-//
-// // 9. Correct for parallax, refraction, and sun's diameter
-// double dec = (pos1.declination + pos2.declination) / 2;
-// double psi = Math.acos(Math.sin(fLatitude) / Math.cos(dec));
-// double x = 0.830725 * DEG_RAD; // parallax+refraction+diameter
-// double y = Math.asin(Math.sin(x) / Math.sin(psi)) * RAD_DEG;
-// double delta_t = 240 * y / Math.cos(dec) / 3600; // hours
-//
-// // 10. Add correction to GSTs, subtract from GSTr
-// gstr -= delta_t;
-// gsts += delta_t;
-//
-// // 11. Convert GST to UT and then to local civil time
-// double ut = gstToUt(rise ? gstr : gsts);
-// //System.out.println((rise?"rise=":"set=") + ut + ", delta_t=" + delta_t);
-// long midnight = DAY_MS * (time / DAY_MS); // Find UT midnight on this day
-// return midnight + (long) (ut * 3600000);
-// }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// /**
-// * Convert local sidereal time to Greenwich sidereal time.
-// * Section 15. Duffett-Smith p.21
-// * @param lst in hours (0..24)
-// * @return GST in hours (0..24)
-// */
-// double lstToGst(double lst) {
-// double delta = fLongitude * 24 / PI2;
-// return normalize(lst - delta, 24);
-// }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// /**
-// * Convert UT to GST on this date.
-// * Section 12. Duffett-Smith p.17
-// * @param ut in hours
-// * @return GST in hours
-// */
-// double utToGst(double ut) {
-// return normalize(getT0() + ut*1.002737909, 24);
-// }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// /**
-// * Convert GST to UT on this date.
-// * Section 13. Duffett-Smith p.18
-// * @param gst in hours
-// * @return UT in hours
-// */
-// double gstToUt(double gst) {
-// return normalize(gst - getT0(), 24) * 0.9972695663;
-// }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// double getT0() {
-// // Common computation for UT <=> GST
-//
-// // Find JD for 0h UT
-// double jd = Math.floor(getJulianDay() - 0.5) + 0.5;
-//
-// double s = jd - 2451545.0;
-// double t = s / 36525.0;
-// double t0 = 6.697374558 + (2400.051336 + 0.000025862*t)*t;
-// return t0;
-// }
-
-// Commented out - currently unused. ICU 2.6, Alan
-// //-------------------------------------------------------------------------
-// // Alternate Sun Rise/Set
-// // See sci.astro FAQ
-// // http://www.faqs.org/faqs/astronomy/faq/part3/section-5.html
-// //-------------------------------------------------------------------------
-//
-// // Note: This method appears to produce inferior accuracy as
-// // compared to getSunRiseSet().
-//
-// /**
-// * TODO Make this public when the entire class is package-private.
-// */
-// /*public*/ long getSunRiseSet3(boolean rise) {
-//
-// // Compute day number for 0.0 Jan 2000 epoch
-// double d = (double)(time - EPOCH_2000_MS) / DAY_MS;
-//
-// // Now compute the Local Sidereal Time, LST:
-// //
-// double LST = 98.9818 + 0.985647352 * d + /*UT*15 + long*/
-// fLongitude*RAD_DEG;
-// //
-// // (east long. positive). Note that LST is here expressed in degrees,
-// // where 15 degrees corresponds to one hour. Since LST really is an angle,
-// // it's convenient to use one unit---degrees---throughout.
-//
-// // COMPUTING THE SUN'S POSITION
-// // ----------------------------
-// //
-// // To be able to compute the Sun's rise/set times, you need to be able to
-// // compute the Sun's position at any time. First compute the "day
-// // number" d as outlined above, for the desired moment. Next compute:
-// //
-// double oblecl = 23.4393 - 3.563E-7 * d;
-// //
-// double w = 282.9404 + 4.70935E-5 * d;
-// double M = 356.0470 + 0.9856002585 * d;
-// double e = 0.016709 - 1.151E-9 * d;
-// //
-// // This is the obliquity of the ecliptic, plus some of the elements of
-// // the Sun's apparent orbit (i.e., really the Earth's orbit): w =
-// // argument of perihelion, M = mean anomaly, e = eccentricity.
-// // Semi-major axis is here assumed to be exactly 1.0 (while not strictly
-// // true, this is still an accurate approximation). Next compute E, the
-// // eccentric anomaly:
-// //
-// double E = M + e*(180/PI) * Math.sin(M*DEG_RAD) * ( 1.0 + e*Math.cos(M*DEG_RAD) );
-// //
-// // where E and M are in degrees. This is it---no further iterations are
-// // needed because we know e has a sufficiently small value. Next compute
-// // the true anomaly, v, and the distance, r:
-// //
-// /* r * cos(v) = */ double A = Math.cos(E*DEG_RAD) - e;
-// /* r * sin(v) = */ double B = Math.sqrt(1 - e*e) * Math.sin(E*DEG_RAD);
-// //
-// // and
-// //
-// // r = sqrt( A*A + B*B )
-// double v = Math.atan2( B, A )*RAD_DEG;
-// //
-// // The Sun's true longitude, slon, can now be computed:
-// //
-// double slon = v + w;
-// //
-// // Since the Sun is always at the ecliptic (or at least very very close to
-// // it), we can use simplified formulae to convert slon (the Sun's ecliptic
-// // longitude) to sRA and sDec (the Sun's RA and Dec):
-// //
-// // sin(slon) * cos(oblecl)
-// // tan(sRA) = -------------------------
-// // cos(slon)
-// //
-// // sin(sDec) = sin(oblecl) * sin(slon)
-// //
-// // As was the case when computing az, the Azimuth, if possible use an
-// // atan2() function to compute sRA.
-//
-// double sRA = Math.atan2(Math.sin(slon*DEG_RAD) * Math.cos(oblecl*DEG_RAD), Math.cos(slon*DEG_RAD))*RAD_DEG;
-//
-// double sin_sDec = Math.sin(oblecl*DEG_RAD) * Math.sin(slon*DEG_RAD);
-// double sDec = Math.asin(sin_sDec)*RAD_DEG;
-//
-// // COMPUTING RISE AND SET TIMES
-// // ----------------------------
-// //
-// // To compute when an object rises or sets, you must compute when it
-// // passes the meridian and the HA of rise/set. Then the rise time is
-// // the meridian time minus HA for rise/set, and the set time is the
-// // meridian time plus the HA for rise/set.
-// //
-// // To find the meridian time, compute the Local Sidereal Time at 0h local
-// // time (or 0h UT if you prefer to work in UT) as outlined above---name
-// // that quantity LST0. The Meridian Time, MT, will now be:
-// //
-// // MT = RA - LST0
-// double MT = normalize(sRA - LST, 360);
-// //
-// // where "RA" is the object's Right Ascension (in degrees!). If negative,
-// // add 360 deg to MT. If the object is the Sun, leave the time as it is,
-// // but if it's stellar, multiply MT by 365.2422/366.2422, to convert from
-// // sidereal to solar time. Now, compute HA for rise/set, name that
-// // quantity HA0:
-// //
-// // sin(h0) - sin(lat) * sin(Dec)
-// // cos(HA0) = ---------------------------------
-// // cos(lat) * cos(Dec)
-// //
-// // where h0 is the altitude selected to represent rise/set. For a purely
-// // mathematical horizon, set h0 = 0 and simplify to:
-// //
-// // cos(HA0) = - tan(lat) * tan(Dec)
-// //
-// // If you want to account for refraction on the atmosphere, set h0 = -35/60
-// // degrees (-35 arc minutes), and if you want to compute the rise/set times
-// // for the Sun's upper limb, set h0 = -50/60 (-50 arc minutes).
-// //
-// double h0 = -50/60 * DEG_RAD;
-//
-// double HA0 = Math.acos(
-// (Math.sin(h0) - Math.sin(fLatitude) * sin_sDec) /
-// (Math.cos(fLatitude) * Math.cos(sDec*DEG_RAD)))*RAD_DEG;
-//
-// // When HA0 has been computed, leave it as it is for the Sun but multiply
-// // by 365.2422/366.2422 for stellar objects, to convert from sidereal to
-// // solar time. Finally compute:
-// //
-// // Rise time = MT - HA0
-// // Set time = MT + HA0
-// //
-// // convert the times from degrees to hours by dividing by 15.
-// //
-// // If you'd like to check that your calculations are accurate or just
-// // need a quick result, check the USNO's Sun or Moon Rise/Set Table,
-// //
- * @param desired The desired longitude.
- * @param next true if the next occurrance of the phase
- * is desired, false for the previous occurrance.
- * @internal
- */
- public long getMoonTime(double desired, boolean next)
- {
- return timeOfAngle( new AngleFunc() {
- public double eval() { return getMoonAge(); } },
- desired,
- SYNODIC_MONTH,
- MINUTE_MS,
- next);
- }
-
- /**
- * Find the next or previous time at which the moon will be in the
- * desired phase.
- *
- * @param desired The desired phase of the moon.
- * @param next true if the next occurrance of the phase
- * is desired, false for the previous occurrance.
- * @internal
- */
- public long getMoonTime(MoonAge desired, boolean next) {
- return getMoonTime(desired.value, next);
- }
-
- /**
- * Returns the time (GMT) of sunrise or sunset on the local date to which
- * this calendar is currently set.
- * @internal
- */
- public long getMoonRiseSet(boolean rise)
- {
- return riseOrSet(new CoordFunc() {
- public Equatorial eval() { return getMoonPosition(); }
- },
- rise,
- .533 * DEG_RAD, // Angular Diameter
- 34 /60.0 * DEG_RAD, // Refraction correction
- MINUTE_MS); // Desired accuracy
- }
-
- //-------------------------------------------------------------------------
- // Interpolation methods for finding the time at which a given event occurs
- //-------------------------------------------------------------------------
-
- private interface AngleFunc {
- public double eval();
- }
-
- private long timeOfAngle(AngleFunc func, double desired,
- double periodDays, long epsilon, boolean next)
- {
- // Find the value of the function at the current time
- double lastAngle = func.eval();
-
- // Find out how far we are from the desired angle
- double deltaAngle = norm2PI(desired - lastAngle) ;
-
- // Using the average period, estimate the next (or previous) time at
- // which the desired angle occurs.
- double deltaT = (deltaAngle + (next ? 0 : -PI2)) * (periodDays*DAY_MS) / PI2;
-
- double lastDeltaT = deltaT; // Liu
- long startTime = time; // Liu
-
- setTime(time + (long)deltaT);
-
- // Now iterate until we get the error below epsilon. Throughout
- // this loop we use normPI to get values in the range -Pi to Pi,
- // since we're using them as correction factors rather than absolute angles.
- do {
- // Evaluate the function at the time we've estimated
- double angle = func.eval();
-
- // Find the # of milliseconds per radian at this point on the curve
- double factor = Math.abs(deltaT / normPI(angle-lastAngle));
-
- // Correct the time estimate based on how far off the angle is
- deltaT = normPI(desired - angle) * factor;
-
- // HACK:
- //
- // If abs(deltaT) begins to diverge we need to quit this loop.
- // This only appears to happen when attempting to locate, for
- // example, a new moon on the day of the new moon. E.g.:
- //
- // This result is correct:
- // newMoon(7508(Mon Jul 23 00:00:00 CST 1990,false))=
- // Sun Jul 22 10:57:41 CST 1990
- //
- // But attempting to make the same call a day earlier causes deltaT
- // to diverge:
- // CalendarAstronomer.timeOfAngle() diverging: 1.348508727575625E9 ->
- // 1.3649828540224032E9
- // newMoon(7507(Sun Jul 22 00:00:00 CST 1990,false))=
- // Sun Jul 08 13:56:15 CST 1990
- //
- // As a temporary solution, we catch this specific condition and
- // adjust our start time by one eighth period days (either forward
- // or backward) and try again.
- // Liu 11/9/00
- if (Math.abs(deltaT) > Math.abs(lastDeltaT)) {
- long delta = (long) (periodDays * DAY_MS / 8);
- setTime(startTime + (next ? delta : -delta));
- return timeOfAngle(func, desired, periodDays, epsilon, next);
- }
-
- lastDeltaT = deltaT;
- lastAngle = angle;
-
- setTime(time + (long)deltaT);
- }
- while (Math.abs(deltaT) > epsilon);
-
- return time;
- }
-
- private interface CoordFunc {
- public Equatorial eval();
- }
-
- private long riseOrSet(CoordFunc func, boolean rise,
- double diameter, double refraction,
- long epsilon)
- {
- Equatorial pos = null;
- double tanL = Math.tan(fLatitude);
- long deltaT = Long.MAX_VALUE;
- int count = 0;
-
- //
- // Calculate the object's position at the current time, then use that
- // position to calculate the time of rising or setting. The position
- // will be different at that time, so iterate until the error is allowable.
- //
- do {
- // See "Practical Astronomy With Your Calculator, section 33.
- pos = func.eval();
- double angle = Math.acos(-tanL * Math.tan(pos.declination));
- double lst = ((rise ? PI2-angle : angle) + pos.ascension ) * 24 / PI2;
-
- // Convert from LST to Universal Time.
- long newTime = lstToUT( lst );
-
- deltaT = newTime - time;
- setTime(newTime);
- }
- while (++ count < 5 && Math.abs(deltaT) > epsilon);
-
- // Calculate the correction due to refraction and the object's angular diameter
- double cosD = Math.cos(pos.declination);
- double psi = Math.acos(Math.sin(fLatitude) / cosD);
- double x = diameter / 2 + refraction;
- double y = Math.asin(Math.sin(x) / Math.sin(psi));
- long delta = (long)((240 * y * RAD_DEG / cosD)*SECOND_MS);
-
- return time + (rise ? -delta : delta);
- }
-
- //-------------------------------------------------------------------------
- // Other utility methods
- //-------------------------------------------------------------------------
-
- /***
- * Given 'value', add or subtract 'range' until 0 <= 'value' < range.
- * The modulus operator.
- */
- private static final double normalize(double value, double range) {
- return value - range * Math.floor(value / range);
- }
-
- /**
- * Normalize an angle so that it's in the range 0 - 2pi.
- * For positive angles this is just (angle % 2pi), but the Java
- * mod operator doesn't work that way for negative numbers....
- */
- private static final double norm2PI(double angle) {
- return normalize(angle, PI2);
- }
-
- /**
- * Normalize an angle into the range -PI - PI
- */
- private static final double normPI(double angle) {
- return normalize(angle + PI, PI2) - PI;
- }
-
- /**
- * Find the "true anomaly" (longitude) of an object from
- * its mean anomaly and the eccentricity of its orbit. This uses
- * an iterative solution to Kepler's equation.
- *
- * @param meanAnomaly The object's longitude calculated as if it were in
- * a regular, circular orbit, measured in radians
- * from the point of perigee.
- *
- * @param eccentricity The eccentricity of the orbit
- *
- * @return The true anomaly (longitude) measured in radians
- */
- private double trueAnomaly(double meanAnomaly, double eccentricity)
- {
- // First, solve Kepler's equation iteratively
- // Duffett-Smith, p.90
- double delta;
- double E = meanAnomaly;
- do {
- delta = E - eccentricity * Math.sin(E) - meanAnomaly;
- E = E - delta / (1 - eccentricity * Math.cos(E));
- }
- while (Math.abs(delta) > 1e-5); // epsilon = 1e-5 rad
-
- return 2.0 * Math.atan( Math.tan(E/2) * Math.sqrt( (1+eccentricity)
- /(1-eccentricity) ) );
- }
-
- /**
- * Return the obliquity of the ecliptic (the angle between the ecliptic
- * and the earth's equator) at the current time. This varies due to
- * the precession of the earth's axis.
- *
- * @return the obliquity of the ecliptic relative to the equator,
- * measured in radians.
- */
- private double eclipticObliquity() {
- if (eclipObliquity == INVALID) {
- final double epoch = 2451545.0; // 2000 AD, January 1.5
-
- double T = (getJulianDay() - epoch) / 36525;
-
- eclipObliquity = 23.439292
- - 46.815/3600 * T
- - 0.0006/3600 * T*T
- + 0.00181/3600 * T*T*T;
-
- eclipObliquity *= DEG_RAD;
- }
- return eclipObliquity;
- }
-
-
- //-------------------------------------------------------------------------
- // Private data
- //-------------------------------------------------------------------------
-
- /**
- * Current time in milliseconds since 1/1/1970 AD
- * @see java.util.Date#getTime
- */
- private long time;
-
- /* These aren't used yet, but they'll be needed for sunset calculations
- * and equatorial to horizon coordinate conversions
- */
- private double fLongitude = 0.0;
- private double fLatitude = 0.0;
- private long fGmtOffset = 0;
-
- //
- // The following fields are used to cache calculated results for improved
- // performance. These values all depend on the current time setting
- // of this object, so the clearCache method is provided.
- //
- static final private double INVALID = Double.MIN_VALUE;
-
- private transient double julianDay = INVALID;
- private transient double julianCentury = INVALID;
- private transient double sunLongitude = INVALID;
- private transient double meanAnomalySun = INVALID;
- private transient double moonLongitude = INVALID;
- private transient double moonEclipLong = INVALID;
- //private transient double meanAnomalyMoon = INVALID;
- private transient double eclipObliquity = INVALID;
- private transient double siderealT0 = INVALID;
- private transient double siderealTime = INVALID;
-
- private transient Equatorial moonPosition = null;
-
- private void clearCache() {
- julianDay = INVALID;
- julianCentury = INVALID;
- sunLongitude = INVALID;
- meanAnomalySun = INVALID;
- moonLongitude = INVALID;
- moonEclipLong = INVALID;
- //meanAnomalyMoon = INVALID;
- eclipObliquity = INVALID;
- siderealTime = INVALID;
- siderealT0 = INVALID;
- moonPosition = null;
- }
-
- //private static void out(String s) {
- // System.out.println(s);
- //}
-
- //private static String deg(double rad) {
- // return Double.toString(rad * RAD_DEG);
- //}
-
- //private static String hours(long ms) {
- // return Double.toString((double)ms / HOUR_MS) + " hours";
- //}
-
- /**
- * @internal
- */
- public String local(long localMillis) {
- return new Date(localMillis - TimeZone.getDefault().getRawOffset()).toString();
- }
-
-
- /**
- * Represents the position of an object in the sky relative to the ecliptic,
- * the plane of the earth's orbit around the Sun.
- * This is a spherical coordinate system in which the latitude
- * specifies the position north or south of the plane of the ecliptic.
- * The longitude specifies the position along the ecliptic plane
- * relative to the "First Point of Aries", which is the Sun's position in the sky
- * at the Vernal Equinox.
- *
- * Note that Ecliptic objects are immutable and cannot be modified
- * once they are constructed. This allows them to be passed and returned by
- * value without worrying about whether other code will modify them.
- *
- * @see CalendarAstronomer.Equatorial
- * @see CalendarAstronomer.Horizon
- * @internal
- */
- public static final class Ecliptic {
- /**
- * Constructs an Ecliptic coordinate object.
- *
- * @param lat The ecliptic latitude, measured in radians.
- * @param lon The ecliptic longitude, measured in radians.
- * @internal
- */
- public Ecliptic(double lat, double lon) {
- latitude = lat;
- longitude = lon;
- }
-
- /**
- * Return a string representation of this object
- * @internal
- */
- public String toString() {
- return Double.toString(longitude*RAD_DEG) + "," + (latitude*RAD_DEG);
- }
-
- /**
- * The ecliptic latitude, in radians. This specifies an object's
- * position north or south of the plane of the ecliptic,
- * with positive angles representing north.
- * @internal
- */
- public final double latitude;
-
- /**
- * The ecliptic longitude, in radians.
- * This specifies an object's position along the ecliptic plane
- * relative to the "First Point of Aries", which is the Sun's position
- * in the sky at the Vernal Equinox,
- * with positive angles representing east.
- *
- * A bit of trivia: the first point of Aries is currently in the
- * constellation Pisces, due to the precession of the earth's axis.
- * @internal
- */
- public final double longitude;
- }
-
- /**
- * Represents the position of an
- * object in the sky relative to the plane of the earth's equator.
- * The Right Ascension specifies the position east or west
- * along the equator, relative to the sun's position at the vernal
- * equinox. The Declination is the position north or south
- * of the equatorial plane.
- *
- * Note that Equatorial objects are immutable and cannot be modified
- * once they are constructed. This allows them to be passed and returned by
- * value without worrying about whether other code will modify them.
- *
- * @see CalendarAstronomer.Ecliptic
- * @see CalendarAstronomer.Horizon
- * @internal
- */
- public static final class Equatorial {
- /**
- * Constructs an Equatorial coordinate object.
- *
- * @param asc The right ascension, measured in radians.
- * @param dec The declination, measured in radians.
- * @internal
- */
- public Equatorial(double asc, double dec) {
- ascension = asc;
- declination = dec;
- }
-
- /**
- * Return a string representation of this object, with the
- * angles measured in degrees.
- * @internal
- */
- public String toString() {
- return Double.toString(ascension*RAD_DEG) + "," + (declination*RAD_DEG);
- }
-
- /**
- * Return a string representation of this object with the right ascension
- * measured in hours, minutes, and seconds.
- * @internal
- */
- public String toHmsString() {
- return radToHms(ascension) + "," + radToDms(declination);
- }
-
- /**
- * The right ascension, in radians.
- * This is the position east or west along the equator
- * relative to the sun's position at the vernal equinox,
- * with positive angles representing East.
- * @internal
- */
- public final double ascension;
-
- /**
- * The declination, in radians.
- * This is the position north or south of the equatorial plane,
- * with positive angles representing north.
- * @internal
- */
- public final double declination;
- }
-
- /**
- * Represents the position of an object in the sky relative to
- * the local horizon.
- * The Altitude represents the object's elevation above the horizon,
- * with objects below the horizon having a negative altitude.
- * The Azimuth is the geographic direction of the object from the
- * observer's position, with 0 representing north. The azimuth increases
- * clockwise from north.
- *
- * Note that Horizon objects are immutable and cannot be modified
- * once they are constructed. This allows them to be passed and returned by
- * value without worrying about whether other code will modify them.
- *
- * @see CalendarAstronomer.Ecliptic
- * @see CalendarAstronomer.Equatorial
- * @internal
- */
- public static final class Horizon {
- /**
- * Constructs a Horizon coordinate object.
- *
- * @param alt The altitude, measured in radians above the horizon.
- * @param azim The azimuth, measured in radians clockwise from north.
- * @internal
- */
- public Horizon(double alt, double azim) {
- altitude = alt;
- azimuth = azim;
- }
-
- /**
- * Return a string representation of this object, with the
- * angles measured in degrees.
- * @internal
- */
- public String toString() {
- return Double.toString(altitude*RAD_DEG) + "," + (azimuth*RAD_DEG);
- }
-
- /**
- * The object's altitude above the horizon, in radians.
- * @internal
- */
- public final double altitude;
-
- /**
- * The object's direction, in radians clockwise from north.
- * @internal
- */
- public final double azimuth;
- }
-
- static private String radToHms(double angle) {
- int hrs = (int) (angle*RAD_HOUR);
- int min = (int)((angle*RAD_HOUR - hrs) * 60);
- int sec = (int)((angle*RAD_HOUR - hrs - min/60.0) * 3600);
-
- return Integer.toString(hrs) + "h" + min + "m" + sec + "s";
- }
-
- static private String radToDms(double angle) {
- int deg = (int) (angle*RAD_DEG);
- int min = (int)((angle*RAD_DEG - deg) * 60);
- int sec = (int)((angle*RAD_DEG - deg - min/60.0) * 3600);
-
- return Integer.toString(deg) + "\u00b0" + min + "'" + sec + "\"";
- }
-}
diff --git a/src/main/java/HygStar.kt b/src/main/java/HygStar.kt
deleted file mode 100644
index cc49cb8..0000000
--- a/src/main/java/HygStar.kt
+++ /dev/null
@@ -1 +0,0 @@
-data class HygStar(val ra: Double, val dec: Double, val mag: Double, val absmag: Double, val properName: String?, val colorIndex: String, val bayerFlamsteed: String, val constellationAbbreviation: String)
\ No newline at end of file
diff --git a/src/main/java/SvgCreator.kt b/src/main/java/SvgCreator.kt
index a9a500d..4d99a88 100644
--- a/src/main/java/SvgCreator.kt
+++ b/src/main/java/SvgCreator.kt
@@ -1,265 +1,216 @@
-import com.opencsv.CSVReaderBuilder
-import com.singulariti.os.ephemeris.StarPositionCalculator
-import com.singulariti.os.ephemeris.domain.Observatory
-import com.singulariti.os.ephemeris.domain.Place
-import com.singulariti.os.ephemeris.domain.Pole
-import com.singulariti.os.ephemeris.domain.Star
-import com.singulariti.os.ephemeris.utils.StarCatalog
+import model.HygParser
import java.io.File
-import java.io.FileReader
import java.io.PrintWriter
-import java.time.Duration
-import java.time.Instant
-import java.time.ZoneId
-import java.time.ZonedDateTime
-import java.util.*
-import java.util.concurrent.TimeUnit
-import java.util.stream.Stream
-import javax.xml.datatype.DatatypeConstants.HOURS
-import kotlin.math.absoluteValue
-
+import kotlin.math.*
/**
- *
-
-180 becomes 18000 -> add 2 digits of precision to everything
+ * This function parses the input file (input/hygdata_v3.csv) and outputs an SVG file containing all stars above the given observer.
+ *
+ * Based this code on explanation found at http://jknight8.tripod.com/CelestialToAzEl.html#the%20source%20code
*/
+
fun main(args: Arraydouble in the range
- * 0 <= phase < 1, interpreted as follows:
- *
- *
- *
- * @see #getMoonAge
- * @internal
- */
- public double getMoonPhase() {
- // See page 147 of "Practial Astronomy with your Calculator",
- // by Peter Duffet-Smith, for details on the algorithm.
- return 0.5 * (1 - Math.cos(getMoonAge()));
- }
-
- private static class MoonAge {
- double value;
- MoonAge(double val) { value = val; }
- }
-
- /**
- * Constant representing a new moon.
- * For use with {@link #getMoonTime(MoonAge, boolean) getMoonTime}
- * @internal
- */
- public static final MoonAge NEW_MOON = new MoonAge(0);
-
- /**
- * Constant representing the moon's first quarter.
- * For use with {@link #getMoonTime(MoonAge, boolean) getMoonTime}
- * @internal
- */
- public static final MoonAge FIRST_QUARTER = new MoonAge(PI/2);
-
- /**
- * Constant representing a full moon.
- * For use with {@link #getMoonTime(MoonAge, boolean) getMoonTime}
- * @internal
- */
- public static final MoonAge FULL_MOON = new MoonAge(PI);
-
- /**
- * Constant representing the moon's last quarter.
- * For use with {@link #getMoonTime(MoonAge, boolean) getMoonTime}
- * @internal
- */
- public static final MoonAge LAST_QUARTER = new MoonAge((PI*3)/2);
-
- /**
- * Find the next or previous time at which the Moon's ecliptic
- * longitude will have the desired value.
- *