include/slib/astro.h

   1 /*
   2  *  astro.h - Astronomical calculations of the slib
   3  *
   4  *  Copyright (C) 2018-2020 Zhang Maiyun
   5  *
   6  *  This file is part of the slib.
   7  *  The slib is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU Lesser General Public License as published by
   9  *  the Free Software Foundation; either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU Lesser General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Lesser General Public License
  18  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #ifndef SLIB_ASTRO_H
  22 #define SLIB_ASTRO_H 1
  23
  24 #include "slib/general.h"
  25
  26 #define S_PI acos(-1.0)
  27
  28 /* trigonometry for degree */
  29 #define dsin(deg) sin(slib_deg2rad(deg))
  30 #define dcos(deg) cos(slib_deg2rad(deg))
  31 #define dtan(deg) tan(slib_deg2rad(deg))
  32 #define dasin(arg) slib_rad2deg(asin(arg))
  33 #define dacos(arg) slib_rad2deg(acos(arg))
  34 #define datan(arg) slib_rad2deg(atan(arg))
  35
  36 _BEGIN_EXTERN_C
  37 OPT double slib_rad2deg(double radians);
  38 OPT double slib_deg2rad(double degrees);
  39 OPT double slib_sun_decl_by_date(int d);
  40 OPT double slib_sf_csha(double latitude, double longitude, double elevation,
  41                         double *solartrans, struct tm *tm);
  42 OPT void slib_sf_sunrise(double latitude, double longitude, double elevation,
  43                          double tz, struct tm *utcnow, struct tm *out_sunrise,
  44                          struct tm *out_sunset);
  45 OPT double slib_julian_day(double julian_date);
  46 OPT double slib_mean_solar_noon(double julian_day, double longitude);
  47 OPT double slib_solar_mean_anomaly(double mean_solar_noon);
  48 OPT double slib_equation_of_the_center_value(double solar_mean_anomaly);
  49 OPT double slib_ecliptic_longitude(double solar_mean_anomaly, double eoc_value);
  50 OPT double slib_solar_transit(double mean_solar_noon, double solar_mean_anomaly,
  51                               double ecliptic_longitude);
  52 OPT double slib_sun_decl(double ecliptic_longitude);
  53 OPT double slib_sunrise_hour_angle(double latitude, double sun_declination);
  54 OPT double slib_corr_sunrise_hour_angle(double latitude, double sun_declination,
  55                                         double elevation);
  56
  57 _END_EXTERN_C
  58 #endif