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Diffstat (limited to 'ext/date/lib/astro.c')
| -rw-r--r-- | ext/date/lib/astro.c | 303 |
1 files changed, 0 insertions, 303 deletions
diff --git a/ext/date/lib/astro.c b/ext/date/lib/astro.c deleted file mode 100644 index f10d4c3a84..0000000000 --- a/ext/date/lib/astro.c +++ /dev/null @@ -1,303 +0,0 @@ -/* - +----------------------------------------------------------------------+ - | PHP Version 5 | - +----------------------------------------------------------------------+ - | Copyright (c) 1997-2006 The PHP Group | - +----------------------------------------------------------------------+ - | This source file is subject to version 3.01 of the PHP license, | - | that is bundled with this package in the file LICENSE, and is | - | available through the world-wide-web at the following url: | - | http://www.php.net/license/3_01.txt | - | If you did not receive a copy of the PHP license and are unable to | - | obtain it through the world-wide-web, please send a note to | - | license@php.net so we can mail you a copy immediately. | - +----------------------------------------------------------------------+ - | Algorithms are taken from a public domain source by Paul | - | Schlyter, who wrote this in December 1992 | - +----------------------------------------------------------------------+ - | Authors: Derick Rethans <derick@derickrethans.nl> | - +----------------------------------------------------------------------+ - */ - -/* $Id$ */ - -#include <stdio.h> -#include <math.h> -#include "timelib.h" - -#define days_since_2000_Jan_0(y,m,d) \ - (367L*(y)-((7*((y)+(((m)+9)/12)))/4)+((275*(m))/9)+(d)-730530L) - -#ifndef PI - #define PI 3.1415926535897932384 -#endif - -#define RADEG ( 180.0 / PI ) -#define DEGRAD ( PI / 180.0 ) - -/* The trigonometric functions in degrees */ - -#define sind(x) sin((x)*DEGRAD) -#define cosd(x) cos((x)*DEGRAD) -#define tand(x) tan((x)*DEGRAD) - -#define atand(x) (RADEG*atan(x)) -#define asind(x) (RADEG*asin(x)) -#define acosd(x) (RADEG*acos(x)) -#define atan2d(y,x) (RADEG*atan2(y,x)) - - -/* Following are some macros around the "workhorse" function __daylen__ */ -/* They mainly fill in the desired values for the reference altitude */ -/* below the horizon, and also selects whether this altitude should */ -/* refer to the Sun's center or its upper limb. */ - - -#include "astro.h" - -/******************************************************************/ -/* This function reduces any angle to within the first revolution */ -/* by subtracting or adding even multiples of 360.0 until the */ -/* result is >= 0.0 and < 360.0 */ -/******************************************************************/ - -#define INV360 (1.0 / 360.0) - -/*****************************************/ -/* Reduce angle to within 0..360 degrees */ -/*****************************************/ -static double astro_revolution(double x) -{ - return (x - 360.0 * floor(x * INV360)); -} - -/*********************************************/ -/* Reduce angle to within +180..+180 degrees */ -/*********************************************/ -static double astro_rev180( double x ) -{ - return (x - 360.0 * floor(x * INV360 + 0.5)); -} - -/*******************************************************************/ -/* This function computes GMST0, the Greenwich Mean Sidereal Time */ -/* at 0h UT (i.e. the sidereal time at the Greenwhich meridian at */ -/* 0h UT). GMST is then the sidereal time at Greenwich at any */ -/* time of the day. I've generalized GMST0 as well, and define it */ -/* as: GMST0 = GMST - UT -- this allows GMST0 to be computed at */ -/* other times than 0h UT as well. While this sounds somewhat */ -/* contradictory, it is very practical: instead of computing */ -/* GMST like: */ -/* */ -/* GMST = (GMST0) + UT * (366.2422/365.2422) */ -/* */ -/* where (GMST0) is the GMST last time UT was 0 hours, one simply */ -/* computes: */ -/* */ -/* GMST = GMST0 + UT */ -/* */ -/* where GMST0 is the GMST "at 0h UT" but at the current moment! */ -/* Defined in this way, GMST0 will increase with about 4 min a */ -/* day. It also happens that GMST0 (in degrees, 1 hr = 15 degr) */ -/* is equal to the Sun's mean longitude plus/minus 180 degrees! */ -/* (if we neglect aberration, which amounts to 20 seconds of arc */ -/* or 1.33 seconds of time) */ -/* */ -/*******************************************************************/ - -static double astro_GMST0(double d) -{ - double sidtim0; - /* Sidtime at 0h UT = L (Sun's mean longitude) + 180.0 degr */ - /* L = M + w, as defined in sunpos(). Since I'm too lazy to */ - /* add these numbers, I'll let the C compiler do it for me. */ - /* Any decent C compiler will add the constants at compile */ - /* time, imposing no runtime or code overhead. */ - sidtim0 = astro_revolution((180.0 + 356.0470 + 282.9404) + (0.9856002585 + 4.70935E-5) * d); - return sidtim0; -} - -/* This function computes the Sun's position at any instant */ - -/******************************************************/ -/* Computes the Sun's ecliptic longitude and distance */ -/* at an instant given in d, number of days since */ -/* 2000 Jan 0.0. The Sun's ecliptic latitude is not */ -/* computed, since it's always very near 0. */ -/******************************************************/ -static void astro_sunpos(double d, double *lon, double *r) -{ - double M, /* Mean anomaly of the Sun */ - w, /* Mean longitude of perihelion */ - /* Note: Sun's mean longitude = M + w */ - e, /* Eccentricity of Earth's orbit */ - E, /* Eccentric anomaly */ - x, y, /* x, y coordinates in orbit */ - v; /* True anomaly */ - - /* Compute mean elements */ - M = astro_revolution(356.0470 + 0.9856002585 * d); - w = 282.9404 + 4.70935E-5 * d; - e = 0.016709 - 1.151E-9 * d; - - /* Compute true longitude and radius vector */ - E = M + e * RADEG * sind(M) * (1.0 + e * cosd(M)); - x = cosd(E) - e; - y = sqrt(1.0 - e*e) * sind(E); - *r = sqrt(x*x + y*y); /* Solar distance */ - v = atan2d(y, x); /* True anomaly */ - *lon = v + w; /* True solar longitude */ - if (*lon >= 360.0) { - *lon -= 360.0; /* Make it 0..360 degrees */ - } -} - -static void astro_sun_RA_dec(double d, double *RA, double *dec, double *r) -{ - double lon, obl_ecl, x, y, z; - - /* Compute Sun's ecliptical coordinates */ - astro_sunpos(d, &lon, r); - - /* Compute ecliptic rectangular coordinates (z=0) */ - x = *r * cosd(lon); - y = *r * sind(lon); - - /* Compute obliquity of ecliptic (inclination of Earth's axis) */ - obl_ecl = 23.4393 - 3.563E-7 * d; - - /* Convert to equatorial rectangular coordinates - x is unchanged */ - z = y * sind(obl_ecl); - y = y * cosd(obl_ecl); - - /* Convert to spherical coordinates */ - *RA = atan2d(y, x); - *dec = atan2d(z, sqrt(x*x + y*y)); -} - -/** - * Note: timestamp = unixtimestamp (NEEDS to be 00:00:00 UT) - * Eastern longitude positive, Western longitude negative - * Northern latitude positive, Southern latitude negative - * The longitude value IS critical in this function! - * altit = the altitude which the Sun should cross - * Set to -35/60 degrees for rise/set, -6 degrees - * for civil, -12 degrees for nautical and -18 - * degrees for astronomical twilight. - * upper_limb: non-zero -> upper limb, zero -> center - * Set to non-zero (e.g. 1) when computing rise/set - * times, and to zero when computing start/end of - * twilight. - * *rise = where to store the rise time - * *set = where to store the set time - * Both times are relative to the specified altitude, - * and thus this function can be used to compute - * various twilight times, as well as rise/set times - * Return value: 0 = sun rises/sets this day, times stored at - * *trise and *tset. - * +1 = sun above the specified "horizon" 24 hours. - * *trise set to time when the sun is at south, - * minus 12 hours while *tset is set to the south - * time plus 12 hours. "Day" length = 24 hours - * -1 = sun is below the specified "horizon" 24 hours - * "Day" length = 0 hours, *trise and *tset are - * both set to the time when the sun is at south. - * - */ -int timelib_astro_rise_set_altitude(timelib_time *t_loc, double lon, double lat, double altit, int upper_limb, double *h_rise, double *h_set, timelib_sll *ts_rise, timelib_sll *ts_set, timelib_sll *ts_transit) -{ - double d, /* Days since 2000 Jan 0.0 (negative before) */ - sr, /* Solar distance, astronomical units */ - sRA, /* Sun's Right Ascension */ - sdec, /* Sun's declination */ - sradius, /* Sun's apparent radius */ - t, /* Diurnal arc */ - tsouth, /* Time when Sun is at south */ - sidtime; /* Local sidereal time */ - timelib_time *t_utc; - timelib_sll timestamp, old_sse; - - int rc = 0; /* Return cde from function - usually 0 */ - - /* Normalize time */ - old_sse = t_loc->sse; - t_loc->h = 12; - t_loc->i = t_loc->s = 0; - timelib_update_ts(t_loc, NULL); - - /* Calculate TS belonging to UTC 00:00 of the current day */ - t_utc = timelib_time_ctor(); - t_utc->y = t_loc->y; - t_utc->m = t_loc->m; - t_utc->d = t_loc->d; - t_utc->h = t_utc->i = t_utc->s = 0; - timelib_update_ts(t_utc, NULL); - - /* Compute d of 12h local mean solar time */ - timestamp = t_loc->sse; - d = timelib_ts_to_juliandate(timestamp) - lon/360.0; - - /* Compute local sidereal time of this moment */ - sidtime = astro_revolution(astro_GMST0(d) + 180.0 + lon); - - /* Compute Sun's RA + Decl at this moment */ - astro_sun_RA_dec( d, &sRA, &sdec, &sr ); - - /* Compute time when Sun is at south - in hours UT */ - tsouth = 12.0 - astro_rev180(sidtime - sRA) / 15.0; - - /* Compute the Sun's apparent radius, degrees */ - sradius = 0.2666 / sr; - - /* Do correction to upper limb, if necessary */ - if (upper_limb) { - altit -= sradius; - } - - /* Compute the diurnal arc that the Sun traverses to reach */ - /* the specified altitude altit: */ - { - double cost; - cost = (sind(altit) - sind(lat) * sind(sdec)) / (cosd(lat) * cosd(sdec)); - *ts_transit = t_utc->sse + (tsouth * 3600); - if (cost >= 1.0) { - rc = -1; - t = 0.0; /* Sun always below altit */ - - *ts_rise = *ts_set = t_utc->sse + (tsouth * 3600); - } else if (cost <= -1.0) { - rc = +1; - t = 12.0; /* Sun always above altit */ - - *ts_rise = t_loc->sse - (12 * 3600); - *ts_set = t_loc->sse + (12 * 3600); - } else { - t = acosd(cost) / 15.0; /* The diurnal arc, hours */ - - /* Store rise and set times - as Unix Timestamp */ - *ts_rise = ((tsouth - t) * 3600) + t_utc->sse; - *ts_set = ((tsouth + t) * 3600) + t_utc->sse; - - *h_rise = (tsouth - t); - *h_set = (tsouth + t); - } - } - - /* Kill temporary time and restore original sse */ - timelib_time_dtor(t_utc); - t_loc->sse = old_sse; - - return rc; -} - -double timelib_ts_to_juliandate(timelib_sll ts) -{ - double tmp; - - tmp = ts; - tmp /= 86400; - tmp += 2440587.5; - tmp -= 2451543; - - return tmp; -} |