1 #include "erfa.h"
2 
eraPnm00a(double date1,double date2,double rbpn[3][3])3 void 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] bias-precession-nutation 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, among
23 **     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 **  This revision:  2021 May 11
57 **
58 **  Copyright (C) 2013-2021, NumFOCUS Foundation.
59 **  Derived, with permission, from the SOFA library.  See notes at end of file.
60 */
61 {
62    double dpsi, deps, epsa, rb[3][3], rp[3][3], rbp[3][3], rn[3][3];
63 
64 
65 /* Obtain the required matrix (discarding other results). */
66    eraPn00a(date1, date2, &dpsi, &deps, &epsa, rb, rp, rbp, rn, rbpn);
67 
68 /* Finished. */
69 
70 }
71 /*----------------------------------------------------------------------
72 **
73 **
74 **  Copyright (C) 2013-2021, NumFOCUS Foundation.
75 **  All rights reserved.
76 **
77 **  This library is derived, with permission, from the International
78 **  Astronomical Union's "Standards of Fundamental Astronomy" library,
79 **  available from http://www.iausofa.org.
80 **
81 **  The ERFA version is intended to retain identical functionality to
82 **  the SOFA library, but made distinct through different function and
83 **  file names, as set out in the SOFA license conditions.  The SOFA
84 **  original has a role as a reference standard for the IAU and IERS,
85 **  and consequently redistribution is permitted only in its unaltered
86 **  state.  The ERFA version is not subject to this restriction and
87 **  therefore can be included in distributions which do not support the
88 **  concept of "read only" software.
89 **
90 **  Although the intent is to replicate the SOFA API (other than
91 **  replacement of prefix names) and results (with the exception of
92 **  bugs;  any that are discovered will be fixed), SOFA is not
93 **  responsible for any errors found in this version of the library.
94 **
95 **  If you wish to acknowledge the SOFA heritage, please acknowledge
96 **  that you are using a library derived from SOFA, rather than SOFA
97 **  itself.
98 **
99 **
100 **  TERMS AND CONDITIONS
101 **
102 **  Redistribution and use in source and binary forms, with or without
103 **  modification, are permitted provided that the following conditions
104 **  are met:
105 **
106 **  1 Redistributions of source code must retain the above copyright
107 **    notice, this list of conditions and the following disclaimer.
108 **
109 **  2 Redistributions in binary form must reproduce the above copyright
110 **    notice, this list of conditions and the following disclaimer in
111 **    the documentation and/or other materials provided with the
112 **    distribution.
113 **
114 **  3 Neither the name of the Standards Of Fundamental Astronomy Board,
115 **    the International Astronomical Union nor the names of its
116 **    contributors may be used to endorse or promote products derived
117 **    from this software without specific prior written permission.
118 **
119 **  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
120 **  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
121 **  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
122 **  FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
123 **  COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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131 **
132 */
133