rfa 0.5.9

A port ERFA to Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

use super::gmst82::*;
use crate::vector_matrix::angle_ops::anp::anp;
use crate::rot_time::eqeq94::*;
///  Greenwich apparent sidereal time (consistent with IAU 1982/94
///  resolutions).
///
///  Given:
///   * uta,utb UT1 as a 2-part Julian Date (Notes 1,2)
///
///  Returned (function value):
///   * Greenwich apparent sidereal time (radians)
///
/// # Notes:
///
///  1) The UT1 date uta+utb is a Julian Date, apportioned in any
///     convenient way between the argument pair.  For example,
///     JD(UT1)=2450123.7 could be expressed in any of these ways, among
///     others:
/// 
///     |     uta     |      utb     |
///     |-------------|--------------|----------------------|
///     |2450123.7    |       0.0    |  (JD method)         |
///     |2451545.0    |   -1421.3    |  (J2000 method)      |
///     |2400000.5    |   50123.2    |  (MJD method)        |
///     |2450123.5    |       0.2    | (date & time method) |
/// 
///     The JD method is the most natural and convenient to use in cases
///     where the loss of several decimal digits of resolution is
///     acceptable.  The J2000 and MJD methods are good compromises
///     between resolution and convenience.  For UT, the date & time
///     method is best matched to the algorithm that is used by the Earth
///     Rotation Angle function, called internally:  maximum precision is
///     delivered when the uta argument is for 0hrs UT1 on the day in
///     question and the utb argument lies in the range 0 to 1, or vice
///     versa.
///
///  2) The result is compatible with the IAU 1982 and 1994 resolutions,
///     except that accuracy has been compromised for the sake of
///     convenience in that UT is used instead of TDB (or TT) to compute
///     the equation of the equinoxes.
///
///  3) This GAST must be used only in conjunction with contemporaneous
///     IAU standards such as 1976 precession, 1980 obliquity and 1982
///     nutation.  It is not compatible with the IAU 2000 resolutions.
///
///  4) The result is returned in the range 0 to 2pi.
///
/// # Called:
///    * gmst82    Greenwich mean sidereal time, IAU 1982
///    * eqeq94    equation of the equinoxes, IAU 1994
///    * anp       normalize angle into range 0 to 2pi
///
///  References:
///   * Explanatory Supplement to the Astronomical Almanac,
///     P. Kenneth Seidelmann (ed), University Science Books (1992)
///   * IAU Resolution C7, Recommendation 3 (1994)
///
///  This revision:  2021 May 11
pub fn gst94(uta: f64, utb: f64)->f64
{


   let gmst82 = gmst82(uta, utb);
   let eqeq94 = eqeq94(uta, utb);
   anp(gmst82  + eqeq94)

/* Finished. */

}