File Coverage

palsrc/palEvp.c

Criterion	Covered	Total	%
statement	13	13	100.0
branch	3	4	75.0
condition			n/a
subroutine			n/a
pod			n/a
total	16	17	94.1

line	stmt	bran	code
1			/*
2			*+
3			* Name:
4			* palEvp
5
6			* Purpose:
7			* Returns the barycentric and heliocentric velocity and position of the
8			* Earth.
9
10			* Language:
11			* Starlink ANSI C
12
13			* Type of Module:
14			* Library routine
15
16			* Invocation:
17			* void palEvp( double date, double deqx, double dvb[3], double dpb[3],
18			* double dvh[3], double dph[3] )
19
20			* Arguments:
21			* date = double (Given)
22			* TDB (loosely ET) as a Modified Julian Date (JD-2400000.5)
23			* deqx = double (Given)
24			* Julian epoch (e.g. 2000.0) of mean equator and equinox of the
25			* vectors returned. If deqx <= 0.0, all vectors are referred to the
26			* mean equator and equinox (FK5) of epoch date.
27			* dvb = double[3] (Returned)
28			* Barycentric velocity (AU/s, AU)
29			* dpb = double[3] (Returned)
30			* Barycentric position (AU/s, AU)
31			* dvh = double[3] (Returned)
32			* heliocentric velocity (AU/s, AU)
33			* dph = double[3] (Returned)
34			* Heliocentric position (AU/s, AU)
35
36			* Description:
37			* Returns the barycentric and heliocentric velocity and position of the
38			* Earth at a given epoch, given with respect to a specified equinox.
39			* For information about accuracy, see the function eraEpv00.
40
41			* Authors:
42			* PTW: Pat Wallace (STFC)
43			* {enter_new_authors_here}
44
45			* History:
46			* 2012-02-13 (PTW):
47			* Initial version.
48			* Adapted with permission from the Fortran SLALIB library.
49			* {enter_further_changes_here}
50
51			* Copyright:
52			* Copyright (C) 2005 Patrick T. Wallace
53			* Copyright (C) 2012 Science and Technology Facilities Council.
54			* All Rights Reserved.
55
56			* Licence:
57			* This program is free software: you can redistribute it and/or
58			* modify it under the terms of the GNU Lesser General Public
59			* License as published by the Free Software Foundation, either
60			* version 3 of the License, or (at your option) any later
61			* version.
62			*
63			* This program is distributed in the hope that it will be useful,
64			* but WITHOUT ANY WARRANTY; without even the implied warranty of
65			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
66			* GNU Lesser General Public License for more details.
67			*
68			* You should have received a copy of the GNU Lesser General
69			* License along with this program. If not, see
70			* .
71
72			* Bugs:
73			* {note_any_bugs_here}
74			*-
75			*/
76
77			#include "pal.h"
78			#include "palmac.h"
79			#include "pal1sofa.h"
80
81	2		void palEvp( double date, double deqx, double dvb[3], double dpb[3],
82			double dvh[3], double dph[3] ){
83
84			/* Local Variables; */
85			int i;
86			double pvh[2][3], pvb[2][3], d1, d2, r[3][3];
87
88			/* BCRS PV-vectors. */
89	2		eraEpv00 ( 2400000.5, date, pvh, pvb );
90
91			/* Was precession to another equinox requested? */
92	2	50	if ( deqx > 0.0 ) {
93
94			/* Yes: compute precession matrix from J2000.0 to deqx. */
95	2		eraEpj2jd ( deqx, &d1, &d2 );
96	2		eraPmat06 ( d1, d2, r );
97
98			/* Rotate the PV-vectors. */
99	2		eraRxpv ( r, pvh, pvh );
100	2		eraRxpv ( r, pvb, pvb );
101			}
102
103			/* Return the required vectors. */
104	8	100	for ( i = 0; i < 3; i++ ) {
105	6		dvh[i] = pvh[1][i] / PAL__SPD;
106	6		dvb[i] = pvb[1][i] / PAL__SPD;
107	6		dph[i] = pvh[0][i];
108	6		dpb[i] = pvb[0][i];
109			}
110	2		}