libnova  v 0.15.0
precession.h
1 /*
2  * This library is free software; you can redistribute it and/or
3  * modify it under the terms of the GNU Lesser General Public
4  * License as published by the Free Software Foundation; either
5  * version 2 of the License, or (at your option) any later version.
6  *
7  * This library is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10  * Lesser General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * along with this program; if not, write to the Free Software
14  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
15  *
16  * Copyright (C) 2000 - 2005 Liam Girdwood
17  */
18 
19 #ifndef _LN_PRECESSION_H
20 #define _LN_PRECESSION_H
21 
22 #include <libnova/ln_types.h>
23 
24 #ifdef __cplusplus
25 extern "C" {
26 #endif
27 
41 /* Equ 20.2, 20.3, 20.4 pg 126 */
42 void LIBNOVA_EXPORT ln_get_equ_prec (struct ln_equ_posn * mean_position, double JD, struct ln_equ_posn * position);
43 
49 /* Equ 20.2, 20.3, 20.4 pg 126 */
50 void LIBNOVA_EXPORT ln_get_equ_prec2 (struct ln_equ_posn * mean_position, double fromJD, double toJD, struct ln_equ_posn * position);
51 
56 /* Equ 20.5, 20.6 pg 128 */
57 void LIBNOVA_EXPORT ln_get_ecl_prec (struct ln_lnlat_posn * mean_position, double JD, struct ln_lnlat_posn * position);
58 
59 #ifdef __cplusplus
60 };
61 #endif
62 
63 #endif
ln_equ_posn::ra
double ra
Definition: ln_types.h:172
ln_deg_to_rad
double LIBNOVA_EXPORT ln_deg_to_rad(double degrees)
degrees to radians
Definition: utility.c:90
ln_range_degrees
double LIBNOVA_EXPORT ln_range_degrees(double angle)
puts a large angle in the correct range 0 - 360 degrees
Definition: utility.c:234
ln_get_ecl_prec
void ln_get_ecl_prec(struct ln_lnlat_posn *mean_position, double JD, struct ln_lnlat_posn *position)
Calculate the effects of precession on ecliptical coordinates.
Definition: precession.c:177
ln_helio_posn::B
double B
Definition: ln_types.h:219
ln_rad_to_deg
double LIBNOVA_EXPORT ln_rad_to_deg(double radians)
radians to degrees
Definition: utility.c:84
ln_get_equ_prec
void ln_get_equ_prec(struct ln_equ_posn *mean_position, double JD, struct ln_equ_posn *position)
Calculate the effects of precession on equatorial coordinates, convert current to J2000.
Definition: precession.c:64
ln_lnlat_posn
Ecliptical (or celestial) Longitude and Latitude.
Definition: ln_types.h:201
ln_equ_posn
Equatorial Coordinates.
Definition: ln_types.h:171
ln_get_equ_prec2
void ln_get_equ_prec2(struct ln_equ_posn *mean_position, double fromJD, double toJD, struct ln_equ_posn *position)
Calculate the effects of precession on equatorial coordinates, between arbitary Jxxxx epochs.
Definition: precession.c:119
ln_equ_posn::dec
double dec
Definition: ln_types.h:173