diff options
Diffstat (limited to 'ext/date/lib/astro.c')
| -rw-r--r-- | ext/date/lib/astro.c | 54 |
1 files changed, 27 insertions, 27 deletions
diff --git a/ext/date/lib/astro.c b/ext/date/lib/astro.c index 84e8a40021..bb7991e474 100644 --- a/ext/date/lib/astro.c +++ b/ext/date/lib/astro.c @@ -115,7 +115,7 @@ static double astro_GMST0(double d) /* 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 */ @@ -177,32 +177,32 @@ static void astro_sun_RA_dec(double d, double *RA, double *dec, double *r) /** * 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. - * + * 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) { |