source: trunk/FACT++/erfa/src/a2tf.c@ 19594

Last change on this file since 19594 was 18921, checked in by tbretz, 8 years ago
Updated to ERFA 1.4.0
File size: 4.8 KB
Line 
1#include "erfa.h"
2
3void eraA2tf(int ndp, double angle, char *sign, int ihmsf[4])
4/*
5** - - - - - - - -
6** e r a A 2 t f
7** - - - - - - - -
8**
9** Decompose radians into hours, minutes, seconds, fraction.
10**
11** Given:
12** ndp int resolution (Note 1)
13** angle double angle in radians
14**
15** Returned:
16** sign char '+' or '-'
17** ihmsf int[4] hours, minutes, seconds, fraction
18**
19** Called:
20** eraD2tf decompose days to hms
21**
22** Notes:
23**
24** 1) The argument ndp is interpreted as follows:
25**
26** ndp resolution
27** : ...0000 00 00
28** -7 1000 00 00
29** -6 100 00 00
30** -5 10 00 00
31** -4 1 00 00
32** -3 0 10 00
33** -2 0 01 00
34** -1 0 00 10
35** 0 0 00 01
36** 1 0 00 00.1
37** 2 0 00 00.01
38** 3 0 00 00.001
39** : 0 00 00.000...
40**
41** 2) The largest positive useful value for ndp is determined by the
42** size of angle, the format of doubles on the target platform, and
43** the risk of overflowing ihmsf[3]. On a typical platform, for
44** angle up to 2pi, the available floating-point precision might
45** correspond to ndp=12. However, the practical limit is typically
46** ndp=9, set by the capacity of a 32-bit int, or ndp=4 if int is
47** only 16 bits.
48**
49** 3) The absolute value of angle may exceed 2pi. In cases where it
50** does not, it is up to the caller to test for and handle the
51** case where angle is very nearly 2pi and rounds up to 24 hours,
52** by testing for ihmsf[0]=24 and setting ihmsf[0-3] to zero.
53**
54** Copyright (C) 2013-2017, NumFOCUS Foundation.
55** Derived, with permission, from the SOFA library. See notes at end of file.
56*/
57{
58/* Scale then use days to h,m,s function. */
59 eraD2tf(ndp, angle/ERFA_D2PI, sign, ihmsf);
60
61 return;
62
63}
64/*----------------------------------------------------------------------
65**
66**
67** Copyright (C) 2013-2017, NumFOCUS Foundation.
68** All rights reserved.
69**
70** This library is derived, with permission, from the International
71** Astronomical Union's "Standards of Fundamental Astronomy" library,
72** available from http://www.iausofa.org.
73**
74** The ERFA version is intended to retain identical functionality to
75** the SOFA library, but made distinct through different function and
76** file names, as set out in the SOFA license conditions. The SOFA
77** original has a role as a reference standard for the IAU and IERS,
78** and consequently redistribution is permitted only in its unaltered
79** state. The ERFA version is not subject to this restriction and
80** therefore can be included in distributions which do not support the
81** concept of "read only" software.
82**
83** Although the intent is to replicate the SOFA API (other than
84** replacement of prefix names) and results (with the exception of
85** bugs; any that are discovered will be fixed), SOFA is not
86** responsible for any errors found in this version of the library.
87**
88** If you wish to acknowledge the SOFA heritage, please acknowledge
89** that you are using a library derived from SOFA, rather than SOFA
90** itself.
91**
92**
93** TERMS AND CONDITIONS
94**
95** Redistribution and use in source and binary forms, with or without
96** modification, are permitted provided that the following conditions
97** are met:
98**
99** 1 Redistributions of source code must retain the above copyright
100** notice, this list of conditions and the following disclaimer.
101**
102** 2 Redistributions in binary form must reproduce the above copyright
103** notice, this list of conditions and the following disclaimer in
104** the documentation and/or other materials provided with the
105** distribution.
106**
107** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
108** the International Astronomical Union nor the names of its
109** contributors may be used to endorse or promote products derived
110** from this software without specific prior written permission.
111**
112** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
113** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
114** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
115** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
116** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
117** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
118** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
119** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
120** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
121** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
122** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
123** POSSIBILITY OF SUCH DAMAGE.
124**
125*/
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