File Coverage

erfasrc/src/s06.c
Criterion Covered Total %
statement 37 37 100.0
branch 20 20 100.0
condition n/a
subroutine n/a
pod n/a
total 57 57 100.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 3           double eraS06(double date1, double date2, double x, double y)
4             /*
5             ** - - - - - - -
6             ** e r a S 0 6
7             ** - - - - - - -
8             **
9             ** The CIO locator s, positioning the Celestial Intermediate Origin on
10             ** the equator of the Celestial Intermediate Pole, given the CIP's X,Y
11             ** coordinates. Compatible with IAU 2006/2000A precession-nutation.
12             **
13             ** Given:
14             ** date1,date2 double TT as a 2-part Julian Date (Note 1)
15             ** x,y double CIP coordinates (Note 3)
16             **
17             ** Returned (function value):
18             ** double the CIO locator s in radians (Note 2)
19             **
20             ** Notes:
21             **
22             ** 1) The TT date date1+date2 is a Julian Date, apportioned in any
23             ** convenient way between the two arguments. For example,
24             ** JD(TT)=2450123.7 could be expressed in any of these ways,
25             ** among others:
26             **
27             ** date1 date2
28             **
29             ** 2450123.7 0.0 (JD method)
30             ** 2451545.0 -1421.3 (J2000 method)
31             ** 2400000.5 50123.2 (MJD method)
32             ** 2450123.5 0.2 (date & time method)
33             **
34             ** The JD method is the most natural and convenient to use in
35             ** cases where the loss of several decimal digits of resolution
36             ** is acceptable. The J2000 method is best matched to the way
37             ** the argument is handled internally and will deliver the
38             ** optimum resolution. The MJD method and the date & time methods
39             ** are both good compromises between resolution and convenience.
40             **
41             ** 2) The CIO locator s is the difference between the right ascensions
42             ** of the same point in two systems: the two systems are the GCRS
43             ** and the CIP,CIO, and the point is the ascending node of the
44             ** CIP equator. The quantity s remains below 0.1 arcsecond
45             ** throughout 1900-2100.
46             **
47             ** 3) The series used to compute s is in fact for s+XY/2, where X and Y
48             ** are the x and y components of the CIP unit vector; this series
49             ** is more compact than a direct series for s would be. This
50             ** function requires X,Y to be supplied by the caller, who is
51             ** responsible for providing values that are consistent with the
52             ** supplied date.
53             **
54             ** 4) The model is consistent with the "P03" precession (Capitaine et
55             ** al. 2003), adopted by IAU 2006 Resolution 1, 2006, and the
56             ** IAU 2000A nutation (with P03 adjustments).
57             **
58             ** Called:
59             ** eraFal03 mean anomaly of the Moon
60             ** eraFalp03 mean anomaly of the Sun
61             ** eraFaf03 mean argument of the latitude of the Moon
62             ** eraFad03 mean elongation of the Moon from the Sun
63             ** eraFaom03 mean longitude of the Moon's ascending node
64             ** eraFave03 mean longitude of Venus
65             ** eraFae03 mean longitude of Earth
66             ** eraFapa03 general accumulated precession in longitude
67             **
68             ** References:
69             **
70             ** Capitaine, N., Wallace, P.T. & Chapront, J., 2003, Astron.
71             ** Astrophys. 432, 355
72             **
73             ** McCarthy, D.D., Petit, G. (eds.) 2004, IERS Conventions (2003),
74             ** IERS Technical Note No. 32, BKG
75             **
76             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
77             ** Derived, with permission, from the SOFA library. See notes at end of file.
78             */
79             {
80             /* Time since J2000.0, in Julian centuries */
81             double t;
82              
83             /* Miscellaneous */
84             int i, j;
85             double a, w0, w1, w2, w3, w4, w5;
86              
87             /* Fundamental arguments */
88             double fa[8];
89              
90             /* Returned value */
91             double s;
92              
93             /* --------------------- */
94             /* The series for s+XY/2 */
95             /* --------------------- */
96              
97             typedef struct {
98             int nfa[8]; /* coefficients of l,l',F,D,Om,LVe,LE,pA */
99             double s, c; /* sine and cosine coefficients */
100             } TERM;
101              
102             /* Polynomial coefficients */
103             static const double sp[] = {
104              
105             /* 1-6 */
106             94.00e-6,
107             3808.65e-6,
108             -122.68e-6,
109             -72574.11e-6,
110             27.98e-6,
111             15.62e-6
112             };
113              
114             /* Terms of order t^0 */
115             static const TERM s0[] = {
116              
117             /* 1-10 */
118             {{ 0, 0, 0, 0, 1, 0, 0, 0}, -2640.73e-6, 0.39e-6 },
119             {{ 0, 0, 0, 0, 2, 0, 0, 0}, -63.53e-6, 0.02e-6 },
120             {{ 0, 0, 2, -2, 3, 0, 0, 0}, -11.75e-6, -0.01e-6 },
121             {{ 0, 0, 2, -2, 1, 0, 0, 0}, -11.21e-6, -0.01e-6 },
122             {{ 0, 0, 2, -2, 2, 0, 0, 0}, 4.57e-6, 0.00e-6 },
123             {{ 0, 0, 2, 0, 3, 0, 0, 0}, -2.02e-6, 0.00e-6 },
124             {{ 0, 0, 2, 0, 1, 0, 0, 0}, -1.98e-6, 0.00e-6 },
125             {{ 0, 0, 0, 0, 3, 0, 0, 0}, 1.72e-6, 0.00e-6 },
126             {{ 0, 1, 0, 0, 1, 0, 0, 0}, 1.41e-6, 0.01e-6 },
127             {{ 0, 1, 0, 0, -1, 0, 0, 0}, 1.26e-6, 0.01e-6 },
128              
129             /* 11-20 */
130             {{ 1, 0, 0, 0, -1, 0, 0, 0}, 0.63e-6, 0.00e-6 },
131             {{ 1, 0, 0, 0, 1, 0, 0, 0}, 0.63e-6, 0.00e-6 },
132             {{ 0, 1, 2, -2, 3, 0, 0, 0}, -0.46e-6, 0.00e-6 },
133             {{ 0, 1, 2, -2, 1, 0, 0, 0}, -0.45e-6, 0.00e-6 },
134             {{ 0, 0, 4, -4, 4, 0, 0, 0}, -0.36e-6, 0.00e-6 },
135             {{ 0, 0, 1, -1, 1, -8, 12, 0}, 0.24e-6, 0.12e-6 },
136             {{ 0, 0, 2, 0, 0, 0, 0, 0}, -0.32e-6, 0.00e-6 },
137             {{ 0, 0, 2, 0, 2, 0, 0, 0}, -0.28e-6, 0.00e-6 },
138             {{ 1, 0, 2, 0, 3, 0, 0, 0}, -0.27e-6, 0.00e-6 },
139             {{ 1, 0, 2, 0, 1, 0, 0, 0}, -0.26e-6, 0.00e-6 },
140              
141             /* 21-30 */
142             {{ 0, 0, 2, -2, 0, 0, 0, 0}, 0.21e-6, 0.00e-6 },
143             {{ 0, 1, -2, 2, -3, 0, 0, 0}, -0.19e-6, 0.00e-6 },
144             {{ 0, 1, -2, 2, -1, 0, 0, 0}, -0.18e-6, 0.00e-6 },
145             {{ 0, 0, 0, 0, 0, 8,-13, -1}, 0.10e-6, -0.05e-6 },
146             {{ 0, 0, 0, 2, 0, 0, 0, 0}, -0.15e-6, 0.00e-6 },
147             {{ 2, 0, -2, 0, -1, 0, 0, 0}, 0.14e-6, 0.00e-6 },
148             {{ 0, 1, 2, -2, 2, 0, 0, 0}, 0.14e-6, 0.00e-6 },
149             {{ 1, 0, 0, -2, 1, 0, 0, 0}, -0.14e-6, 0.00e-6 },
150             {{ 1, 0, 0, -2, -1, 0, 0, 0}, -0.14e-6, 0.00e-6 },
151             {{ 0, 0, 4, -2, 4, 0, 0, 0}, -0.13e-6, 0.00e-6 },
152              
153             /* 31-33 */
154             {{ 0, 0, 2, -2, 4, 0, 0, 0}, 0.11e-6, 0.00e-6 },
155             {{ 1, 0, -2, 0, -3, 0, 0, 0}, -0.11e-6, 0.00e-6 },
156             {{ 1, 0, -2, 0, -1, 0, 0, 0}, -0.11e-6, 0.00e-6 }
157             };
158              
159             /* Terms of order t^1 */
160             static const TERM s1[] = {
161              
162             /* 1 - 3 */
163             {{ 0, 0, 0, 0, 2, 0, 0, 0}, -0.07e-6, 3.57e-6 },
164             {{ 0, 0, 0, 0, 1, 0, 0, 0}, 1.73e-6, -0.03e-6 },
165             {{ 0, 0, 2, -2, 3, 0, 0, 0}, 0.00e-6, 0.48e-6 }
166             };
167              
168             /* Terms of order t^2 */
169             static const TERM s2[] = {
170              
171             /* 1-10 */
172             {{ 0, 0, 0, 0, 1, 0, 0, 0}, 743.52e-6, -0.17e-6 },
173             {{ 0, 0, 2, -2, 2, 0, 0, 0}, 56.91e-6, 0.06e-6 },
174             {{ 0, 0, 2, 0, 2, 0, 0, 0}, 9.84e-6, -0.01e-6 },
175             {{ 0, 0, 0, 0, 2, 0, 0, 0}, -8.85e-6, 0.01e-6 },
176             {{ 0, 1, 0, 0, 0, 0, 0, 0}, -6.38e-6, -0.05e-6 },
177             {{ 1, 0, 0, 0, 0, 0, 0, 0}, -3.07e-6, 0.00e-6 },
178             {{ 0, 1, 2, -2, 2, 0, 0, 0}, 2.23e-6, 0.00e-6 },
179             {{ 0, 0, 2, 0, 1, 0, 0, 0}, 1.67e-6, 0.00e-6 },
180             {{ 1, 0, 2, 0, 2, 0, 0, 0}, 1.30e-6, 0.00e-6 },
181             {{ 0, 1, -2, 2, -2, 0, 0, 0}, 0.93e-6, 0.00e-6 },
182              
183             /* 11-20 */
184             {{ 1, 0, 0, -2, 0, 0, 0, 0}, 0.68e-6, 0.00e-6 },
185             {{ 0, 0, 2, -2, 1, 0, 0, 0}, -0.55e-6, 0.00e-6 },
186             {{ 1, 0, -2, 0, -2, 0, 0, 0}, 0.53e-6, 0.00e-6 },
187             {{ 0, 0, 0, 2, 0, 0, 0, 0}, -0.27e-6, 0.00e-6 },
188             {{ 1, 0, 0, 0, 1, 0, 0, 0}, -0.27e-6, 0.00e-6 },
189             {{ 1, 0, -2, -2, -2, 0, 0, 0}, -0.26e-6, 0.00e-6 },
190             {{ 1, 0, 0, 0, -1, 0, 0, 0}, -0.25e-6, 0.00e-6 },
191             {{ 1, 0, 2, 0, 1, 0, 0, 0}, 0.22e-6, 0.00e-6 },
192             {{ 2, 0, 0, -2, 0, 0, 0, 0}, -0.21e-6, 0.00e-6 },
193             {{ 2, 0, -2, 0, -1, 0, 0, 0}, 0.20e-6, 0.00e-6 },
194              
195             /* 21-25 */
196             {{ 0, 0, 2, 2, 2, 0, 0, 0}, 0.17e-6, 0.00e-6 },
197             {{ 2, 0, 2, 0, 2, 0, 0, 0}, 0.13e-6, 0.00e-6 },
198             {{ 2, 0, 0, 0, 0, 0, 0, 0}, -0.13e-6, 0.00e-6 },
199             {{ 1, 0, 2, -2, 2, 0, 0, 0}, -0.12e-6, 0.00e-6 },
200             {{ 0, 0, 2, 0, 0, 0, 0, 0}, -0.11e-6, 0.00e-6 }
201             };
202              
203             /* Terms of order t^3 */
204             static const TERM s3[] = {
205              
206             /* 1-4 */
207             {{ 0, 0, 0, 0, 1, 0, 0, 0}, 0.30e-6, -23.42e-6 },
208             {{ 0, 0, 2, -2, 2, 0, 0, 0}, -0.03e-6, -1.46e-6 },
209             {{ 0, 0, 2, 0, 2, 0, 0, 0}, -0.01e-6, -0.25e-6 },
210             {{ 0, 0, 0, 0, 2, 0, 0, 0}, 0.00e-6, 0.23e-6 }
211             };
212              
213             /* Terms of order t^4 */
214             static const TERM s4[] = {
215              
216             /* 1-1 */
217             {{ 0, 0, 0, 0, 1, 0, 0, 0}, -0.26e-6, -0.01e-6 }
218             };
219              
220             /* Number of terms in the series */
221             static const int NS0 = (int) (sizeof s0 / sizeof (TERM));
222             static const int NS1 = (int) (sizeof s1 / sizeof (TERM));
223             static const int NS2 = (int) (sizeof s2 / sizeof (TERM));
224             static const int NS3 = (int) (sizeof s3 / sizeof (TERM));
225             static const int NS4 = (int) (sizeof s4 / sizeof (TERM));
226              
227             /*--------------------------------------------------------------------*/
228              
229             /* Interval between fundamental epoch J2000.0 and current date (JC). */
230 3           t = ((date1 - ERFA_DJ00) + date2) / ERFA_DJC;
231              
232             /* Fundamental Arguments (from IERS Conventions 2003) */
233              
234             /* Mean anomaly of the Moon. */
235 3           fa[0] = eraFal03(t);
236              
237             /* Mean anomaly of the Sun. */
238 3           fa[1] = eraFalp03(t);
239              
240             /* Mean longitude of the Moon minus that of the ascending node. */
241 3           fa[2] = eraFaf03(t);
242              
243             /* Mean elongation of the Moon from the Sun. */
244 3           fa[3] = eraFad03(t);
245              
246             /* Mean longitude of the ascending node of the Moon. */
247 3           fa[4] = eraFaom03(t);
248              
249             /* Mean longitude of Venus. */
250 3           fa[5] = eraFave03(t);
251              
252             /* Mean longitude of Earth. */
253 3           fa[6] = eraFae03(t);
254              
255             /* General precession in longitude. */
256 3           fa[7] = eraFapa03(t);
257              
258             /* Evaluate s. */
259             w0 = sp[0];
260             w1 = sp[1];
261             w2 = sp[2];
262             w3 = sp[3];
263             w4 = sp[4];
264             w5 = sp[5];
265              
266 102 100         for (i = NS0-1; i >= 0; i--) {
267             a = 0.0;
268 891 100         for (j = 0; j < 8; j++) {
269 792           a += (double)s0[i].nfa[j] * fa[j];
270             }
271 99           w0 += s0[i].s * sin(a) + s0[i].c * cos(a);
272             }
273              
274 12 100         for (i = NS1-1; i >= 0; i--) {
275             a = 0.0;
276 81 100         for (j = 0; j < 8; j++) {
277 72           a += (double)s1[i].nfa[j] * fa[j];
278             }
279 9           w1 += s1[i].s * sin(a) + s1[i].c * cos(a);
280             }
281              
282 78 100         for (i = NS2-1; i >= 0; i--) {
283             a = 0.0;
284 675 100         for (j = 0; j < 8; j++) {
285 600           a += (double)s2[i].nfa[j] * fa[j];
286             }
287 75           w2 += s2[i].s * sin(a) + s2[i].c * cos(a);
288             }
289              
290 15 100         for (i = NS3-1; i >= 0; i--) {
291             a = 0.0;
292 108 100         for (j = 0; j < 8; j++) {
293 96           a += (double)s3[i].nfa[j] * fa[j];
294             }
295 12           w3 += s3[i].s * sin(a) + s3[i].c * cos(a);
296             }
297              
298 6 100         for (i = NS4-1; i >= 0; i--) {
299             a = 0.0;
300 27 100         for (j = 0; j < 8; j++) {
301 24           a += (double)s4[i].nfa[j] * fa[j];
302             }
303 3           w4 += s4[i].s * sin(a) + s4[i].c * cos(a);
304             }
305              
306 6           s = (w0 +
307 3           (w1 +
308 3           (w2 +
309 3           (w3 +
310 3           (w4 +
311 18           w5 * t) * t) * t) * t) * t) * ERFA_DAS2R - x*y/2.0;
312              
313 3           return s;
314              
315             }
316             /*----------------------------------------------------------------------
317             **
318             **
319             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
320             ** All rights reserved.
321             **
322             ** This library is derived, with permission, from the International
323             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
324             ** available from http://www.iausofa.org.
325             **
326             ** The ERFA version is intended to retain identical functionality to
327             ** the SOFA library, but made distinct through different function and
328             ** file names, as set out in the SOFA license conditions. The SOFA
329             ** original has a role as a reference standard for the IAU and IERS,
330             ** and consequently redistribution is permitted only in its unaltered
331             ** state. The ERFA version is not subject to this restriction and
332             ** therefore can be included in distributions which do not support the
333             ** concept of "read only" software.
334             **
335             ** Although the intent is to replicate the SOFA API (other than
336             ** replacement of prefix names) and results (with the exception of
337             ** bugs; any that are discovered will be fixed), SOFA is not
338             ** responsible for any errors found in this version of the library.
339             **
340             ** If you wish to acknowledge the SOFA heritage, please acknowledge
341             ** that you are using a library derived from SOFA, rather than SOFA
342             ** itself.
343             **
344             **
345             ** TERMS AND CONDITIONS
346             **
347             ** Redistribution and use in source and binary forms, with or without
348             ** modification, are permitted provided that the following conditions
349             ** are met:
350             **
351             ** 1 Redistributions of source code must retain the above copyright
352             ** notice, this list of conditions and the following disclaimer.
353             **
354             ** 2 Redistributions in binary form must reproduce the above copyright
355             ** notice, this list of conditions and the following disclaimer in
356             ** the documentation and/or other materials provided with the
357             ** distribution.
358             **
359             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
360             ** the International Astronomical Union nor the names of its
361             ** contributors may be used to endorse or promote products derived
362             ** from this software without specific prior written permission.
363             **
364             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
365             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
366             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
367             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
368             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
369             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
370             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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372             ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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374             ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
375             ** POSSIBILITY OF SUCH DAMAGE.
376             **
377             */