update ast 8.6.2

1 files changed, 151 insertions, 0 deletions

diff --git a/ast/erfa/c2ibpn.c b/ast/erfa/c2ibpn.c
new file mode 100644
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+++ b/ast/erfa/c2ibpn.c
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+#include "erfa.h"
+
+void eraC2ibpn(double date1, double date2, double rbpn[3][3],
+               double rc2i[3][3])
+/*
+**  - - - - - - - - - -
+**   e r a C 2 i b p n
+**  - - - - - - - - - -
+**
+**  Form the celestial-to-intermediate matrix for a given date given
+**  the bias-precession-nutation matrix.  IAU 2000.
+**
+**  Given:
+**     date1,date2 double       TT as a 2-part Julian Date (Note 1)
+**     rbpn        double[3][3] celestial-to-true matrix (Note 2)
+**
+**  Returned:
+**     rc2i        double[3][3] celestial-to-intermediate matrix (Note 3)
+**
+**  Notes:
+**
+**  1) The TT date date1+date2 is a Julian Date, apportioned in any
+**     convenient way between the two arguments.  For example,
+**     JD(TT)=2450123.7 could be expressed in any of these ways,
+**     among others:
+**
+**            date1          date2
+**
+**         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 method is best matched to the way
+**     the argument is handled internally and will deliver the
+**     optimum resolution.  The MJD method and the date & time methods
+**     are both good compromises between resolution and convenience.
+**
+**  2) The matrix rbpn transforms vectors from GCRS to true equator (and
+**     CIO or equinox) of date.  Only the CIP (bottom row) is used.
+**
+**  3) The matrix rc2i is the first stage in the transformation from
+**     celestial to terrestrial coordinates:
+**
+**        [TRS] = RPOM * R_3(ERA) * rc2i * [CRS]
+**
+**              = RC2T * [CRS]
+**
+**     where [CRS] is a vector in the Geocentric Celestial Reference
+**     System and [TRS] is a vector in the International Terrestrial
+**     Reference System (see IERS Conventions 2003), ERA is the Earth
+**     Rotation Angle and RPOM is the polar motion matrix.
+**
+**  4) Although its name does not include "00", This function is in fact
+**     specific to the IAU 2000 models.
+**
+**  Called:
+**     eraBpn2xy    extract CIP X,Y coordinates from NPB matrix
+**     eraC2ixy     celestial-to-intermediate matrix, given X,Y
+**
+**  References:
+**     "Expressions for the Celestial Intermediate Pole and Celestial
+**     Ephemeris Origin consistent with the IAU 2000A precession-
+**     nutation model", Astron.Astrophys. 400, 1145-1154 (2003)
+**
+**     n.b. The celestial ephemeris origin (CEO) was renamed "celestial
+**          intermediate origin" (CIO) by IAU 2006 Resolution 2.
+**
+**     McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
+**     IERS Technical Note No. 32, BKG (2004)
+**
+**  Copyright (C) 2013-2016, NumFOCUS Foundation.
+**  Derived, with permission, from the SOFA library.  See notes at end of file.
+*/
+{
+   double x, y;
+
+
+/* Extract the X,Y coordinates. */
+   eraBpn2xy(rbpn, &x, &y);
+
+/* Form the celestial-to-intermediate matrix (n.b. IAU 2000 specific). */
+   eraC2ixy(date1, date2, x, y, rc2i);
+
+   return;
+
+}
+/*----------------------------------------------------------------------
+**  
+**  
+**  Copyright (C) 2013-2016, NumFOCUS Foundation.
+**  All rights reserved.
+**  
+**  This library is derived, with permission, from the International
+**  Astronomical Union's "Standards of Fundamental Astronomy" library,
+**  available from http://www.iausofa.org.
+**  
+**  The ERFA version is intended to retain identical functionality to
+**  the SOFA library, but made distinct through different function and
+**  file names, as set out in the SOFA license conditions.  The SOFA
+**  original has a role as a reference standard for the IAU and IERS,
+**  and consequently redistribution is permitted only in its unaltered
+**  state.  The ERFA version is not subject to this restriction and
+**  therefore can be included in distributions which do not support the
+**  concept of "read only" software.
+**  
+**  Although the intent is to replicate the SOFA API (other than
+**  replacement of prefix names) and results (with the exception of
+**  bugs;  any that are discovered will be fixed), SOFA is not
+**  responsible for any errors found in this version of the library.
+**  
+**  If you wish to acknowledge the SOFA heritage, please acknowledge
+**  that you are using a library derived from SOFA, rather than SOFA
+**  itself.
+**  
+**  
+**  TERMS AND CONDITIONS
+**  
+**  Redistribution and use in source and binary forms, with or without
+**  modification, are permitted provided that the following conditions
+**  are met:
+**  
+**  1 Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+**  
+**  2 Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in
+**    the documentation and/or other materials provided with the
+**    distribution.
+**  
+**  3 Neither the name of the Standards Of Fundamental Astronomy Board,
+**    the International Astronomical Union nor the names of its
+**    contributors may be used to endorse or promote products derived
+**    from this software without specific prior written permission.
+**  
+**  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+**  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+**  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+**  FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+**  COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+**  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+**  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+**  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+**  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+**  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+**  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+**  POSSIBILITY OF SUCH DAMAGE.
+**  
+*/