libnova v 0.15.0

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lunar.c

Examples of how to use Lunar functions.

/*
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Copyright (C) 2003 Liam Girdwood <liam@gnova.org>
A simple example showing some lunar calculations.
*/
#include <stdio.h>
#include <libnova/lunar.h>
#include <libnova/julian_day.h>
#include <libnova/rise_set.h>
#include <libnova/transform.h>
void print_date (char * title, struct ln_zonedate* date)
{
printf ("\n%s\n",title);
printf (" Year : %d\n", date->years);
printf (" Month : %d\n", date->months);
printf (" Day : %d\n", date->days);
printf (" Hours : %d\n", date->hours);
printf (" Minutes : %d\n", date->minutes);
printf (" Seconds : %f\n", date->seconds);
}
int main (int argc, char* argv[])
{
double JD;
struct ln_rect_posn moon;
struct ln_equ_posn equ;
struct ln_lnlat_posn ecl;
struct ln_lnlat_posn observer;
struct ln_rst_time rst;
struct ln_zonedate rise, transit, set;
/* observers location (Edinburgh), used to calc rst */
observer.lat = 55.92; /* 55.92 N */
observer.lng = -3.18; /* 3.18 W */
/* get the julian day from the local system time */
JD = ln_get_julian_from_sys();
printf ("JD %f\n",JD);
/* get the lunar geopcentric position in km, earth is at 0,0,0 */
ln_get_lunar_geo_posn (JD, &moon, 0);
printf ("lunar x %f y %f z %f\n",moon.X, moon.Y, moon.Z);
/* Long Lat */
ln_get_lunar_ecl_coords (JD, &ecl, 0);
printf ("lunar long %f lat %f\n",ecl.lng, ecl.lat);
/* RA, DEC */
ln_get_lunar_equ_coords (JD, &equ);
printf ("lunar RA %f Dec %f\n",equ.ra, equ.dec);
/* moon earth distance */
printf ("lunar distance km %f\n", ln_get_lunar_earth_dist(JD));
/* lunar disk, phase and bright limb */
printf ("lunar disk %f\n", ln_get_lunar_disk(JD));
printf ("lunar phase %f\n", ln_get_lunar_phase(JD));
printf ("lunar bright limb %f\n", ln_get_lunar_bright_limb(JD));
/* rise, set and transit time */
if (ln_get_lunar_rst (JD, &observer, &rst) == 1)
printf ("Moon is circumpolar\n");
else {
ln_get_local_date (rst.rise, &rise);
ln_get_local_date (rst.transit, &transit);
ln_get_local_date (rst.set, &set);
print_date ("Rise", &rise);
print_date ("Transit", &transit);
print_date ("Set", &set);
}
/* rise, set and transit time */
if (ln_get_lunar_rst (JD - 24, &observer, &rst) == 1)
printf ("Moon is circumpolar\n");
else {
ln_get_local_date (rst.rise, &rise);
ln_get_local_date (rst.transit, &transit);
ln_get_local_date (rst.set, &set);
print_date ("Rise", &rise);
print_date ("Transit", &transit);
print_date ("Set", &set);
}
/* rise, set and transit time */
if (ln_get_lunar_rst (JD - 25, &observer, &rst) == 1)
printf ("Moon is circumpolar\n");
else {
ln_get_local_date (rst.rise, &rise);
ln_get_local_date (rst.transit, &transit);
ln_get_local_date (rst.set, &set);
print_date ("Rise", &rise);
print_date ("Transit", &transit);
print_date ("Set", &set);
}
return 0;
}