source: branches/FACT++_part_filenames/erfa/src/pnm00a.c@ 18796

Last change on this file since 18796 was 18711, checked in by tbretz, 8 years ago
Updated to ERFA 1.3.0 (no relevant code change except the leap second at the beginning of 2017)
File size: 5.2 KB
Line 
1#include "erfa.h"
2
3void eraPnm00a(double date1, double date2, double rbpn[3][3])
4/*
5** - - - - - - - - - -
6** e r a P n m 0 0 a
7** - - - - - - - - - -
8**
9** Form the matrix of precession-nutation for a given date (including
10** frame bias), equinox-based, IAU 2000A model.
11**
12** Given:
13** date1,date2 double TT as a 2-part Julian Date (Note 1)
14**
15** Returned:
16** rbpn double[3][3] classical NPB matrix (Note 2)
17**
18** Notes:
19**
20** 1) The TT date date1+date2 is a Julian Date, apportioned in any
21** convenient way between the two arguments. For example,
22** JD(TT)=2450123.7 could be expressed in any of these ways,
23** among others:
24**
25** date1 date2
26**
27** 2450123.7 0.0 (JD method)
28** 2451545.0 -1421.3 (J2000 method)
29** 2400000.5 50123.2 (MJD method)
30** 2450123.5 0.2 (date & time method)
31**
32** The JD method is the most natural and convenient to use in
33** cases where the loss of several decimal digits of resolution
34** is acceptable. The J2000 method is best matched to the way
35** the argument is handled internally and will deliver the
36** optimum resolution. The MJD method and the date & time methods
37** are both good compromises between resolution and convenience.
38**
39** 2) The matrix operates in the sense V(date) = rbpn * V(GCRS), where
40** the p-vector V(date) is with respect to the true equatorial triad
41** of date date1+date2 and the p-vector V(GCRS) is with respect to
42** the Geocentric Celestial Reference System (IAU, 2000).
43**
44** 3) A faster, but slightly less accurate result (about 1 mas), can be
45** obtained by using instead the eraPnm00b function.
46**
47** Called:
48** eraPn00a bias/precession/nutation, IAU 2000A
49**
50** Reference:
51**
52** IAU: Trans. International Astronomical Union, Vol. XXIVB; Proc.
53** 24th General Assembly, Manchester, UK. Resolutions B1.3, B1.6.
54** (2000)
55**
56** Copyright (C) 2013-2016, NumFOCUS Foundation.
57** Derived, with permission, from the SOFA library. See notes at end of file.
58*/
59{
60 double dpsi, deps, epsa, rb[3][3], rp[3][3], rbp[3][3], rn[3][3];
61
62
63/* Obtain the required matrix (discarding other results). */
64 eraPn00a(date1, date2, &dpsi, &deps, &epsa, rb, rp, rbp, rn, rbpn);
65
66 return;
67
68}
69/*----------------------------------------------------------------------
70**
71**
72** Copyright (C) 2013-2016, NumFOCUS Foundation.
73** All rights reserved.
74**
75** This library is derived, with permission, from the International
76** Astronomical Union's "Standards of Fundamental Astronomy" library,
77** available from http://www.iausofa.org.
78**
79** The ERFA version is intended to retain identical functionality to
80** the SOFA library, but made distinct through different function and
81** file names, as set out in the SOFA license conditions. The SOFA
82** original has a role as a reference standard for the IAU and IERS,
83** and consequently redistribution is permitted only in its unaltered
84** state. The ERFA version is not subject to this restriction and
85** therefore can be included in distributions which do not support the
86** concept of "read only" software.
87**
88** Although the intent is to replicate the SOFA API (other than
89** replacement of prefix names) and results (with the exception of
90** bugs; any that are discovered will be fixed), SOFA is not
91** responsible for any errors found in this version of the library.
92**
93** If you wish to acknowledge the SOFA heritage, please acknowledge
94** that you are using a library derived from SOFA, rather than SOFA
95** itself.
96**
97**
98** TERMS AND CONDITIONS
99**
100** Redistribution and use in source and binary forms, with or without
101** modification, are permitted provided that the following conditions
102** are met:
103**
104** 1 Redistributions of source code must retain the above copyright
105** notice, this list of conditions and the following disclaimer.
106**
107** 2 Redistributions in binary form must reproduce the above copyright
108** notice, this list of conditions and the following disclaimer in
109** the documentation and/or other materials provided with the
110** distribution.
111**
112** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
113** the International Astronomical Union nor the names of its
114** contributors may be used to endorse or promote products derived
115** from this software without specific prior written permission.
116**
117** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
118** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
119** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
120** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
121** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
122** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
123** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
124** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
125** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
126** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
127** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
128** POSSIBILITY OF SUCH DAMAGE.
129**
130*/
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