#include "sofam.h"
void iauPn00(double date1, double date2, double dpsi, double deps,
double *epsa,
double rb[3][3], double rp[3][3], double rbp[3][3],
double rn[3][3], double rbpn[3][3])
/*
** - - - - - - - -
** i a u P n 0 0
** - - - - - - - -
**
** Precession-nutation, IAU 2000 model: a multi-purpose function,
** supporting classical (equinox-based) use directly and CIO-based
** use indirectly.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards Of Fundamental Astronomy) software collection.
**
** Status: support function.
**
** Given:
** date1,date2 double TT as a 2-part Julian Date (Note 1)
** dpsi,deps double nutation (Note 2)
**
** Returned:
** epsa double mean obliquity (Note 3)
** rb double[3][3] frame bias matrix (Note 4)
** rp double[3][3] precession matrix (Note 5)
** rbp double[3][3] bias-precession matrix (Note 6)
** rn double[3][3] nutation matrix (Note 7)
** rbpn double[3][3] GCRS-to-true matrix (Note 8)
**
** 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 caller is responsible for providing the nutation components;
** they are in longitude and obliquity, in radians and are with
** respect to the equinox and ecliptic of date. For high-accuracy
** applications, free core nutation should be included as well as
** any other relevant corrections to the position of the CIP.
**
** 3) The returned mean obliquity is consistent with the IAU 2000
** precession-nutation models.
**
** 4) The matrix rb transforms vectors from GCRS to J2000 mean equator
** and equinox by applying frame bias.
**
** 5) The matrix rp transforms vectors from J2000 mean equator and
** equinox to mean equator and equinox of date by applying
** precession.
**
** 6) The matrix rbp transforms vectors from GCRS to mean equator and
** equinox of date by applying frame bias then precession. It is
** the product rp x rb.
**
** 7) The matrix rn transforms vectors from mean equator and equinox of
** date to true equator and equinox of date by applying the nutation
** (luni-solar + planetary).
**
** 8) The matrix rbpn transforms vectors from GCRS to true equator and
** equinox of date. It is the product rn x rbp, applying frame
** bias, precession and nutation in that order.
**
** 9) It is permissible to re-use the same array in the returned
** arguments. The arrays are filled in the order given.
**
** Called:
** iauPr00 IAU 2000 precession adjustments
** iauObl80 mean obliquity, IAU 1980
** iauBp00 frame bias and precession matrices, IAU 2000
** iauCr copy r-matrix
** iauNumat form nutation matrix
** iauRxr product of two r-matrices
**
** Reference:
**
** Capitaine, N., Chapront, J., Lambert, S. and Wallace, P.,
** "Expressions for the Celestial Intermediate Pole and Celestial
** Ephemeris Origin consistent with the IAU 2000A precession-
** nutation model", Astronomy & Astrophysics, 400, 1145-1154 (2003)
**
** n.b. The celestial ephemeris origin (CEO) was renamed "celestial
** intermediate origin" (CIO) by IAU 2006 Resolution 2.
**
** This revision: 2008 November 18
**
** Copyright (C) 2008 IAU SOFA Review Board. See notes at end.
*/
{
double dpsipr, depspr, rbpw[3][3], rnw[3][3];
/* IAU 2000 precession-rate adjustments. */
iauPr00(date1, date2, &dpsipr, &depspr);
/* Mean obliquity, consistent with IAU 2000 precession-nutation. */
*epsa = iauObl80(date1, date2) + depspr;
/* Frame bias and precession matrices and their product. */
iauBp00(date1, date2, rb, rp, rbpw);
iauCr(rbpw, rbp);
/* Nutation matrix. */
iauNumat(*epsa, dpsi, deps, rnw);
iauCr(rnw, rn);
/* Bias-precession-nutation matrix (classical). */
iauRxr(rnw, rbpw, rbpn);
return;
/*-----------------------------------------------------------------------
**
** Copyright (C) 2008
** Standards Of Fundamental Astronomy Review Board
** of the International Astronomical Union.
**
** =====================
** SOFA Software License
** =====================
**
** NOTICE TO USER:
**
** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS
** WHICH APPLY TO ITS USE.
**
** 1. The Software is owned by the IAU SOFA Review Board ("the Board").
**
** 2. Permission is granted to anyone to use the SOFA software for any
** purpose, including commercial applications, free of charge and
** without payment of royalties, subject to the conditions and
** restrictions listed below.
**
** 3. You (the user) may copy and adapt the SOFA software and its
** algorithms for your own purposes and you may copy and distribute
** a resulting "derived work" to others on a world-wide, royalty-free
** basis, provided that the derived work complies with the following
** requirements:
**
** a) Your work shall be marked or carry a statement that it (i) uses
** routines and computations derived by you from software provided
** by SOFA under license to you; and (ii) does not contain
** software provided by SOFA or software that has been distributed
** by or endorsed by SOFA.
**
** b) The source code of your derived work must contain descriptions
** of how the derived work is based upon and/or differs from the
** original SOFA software.
**
** c) The name(s) of all routine(s) that you distribute shall differ
** from the SOFA names, even when the SOFA content has not been
** otherwise changed.
**
** d) The routine-naming prefix "iau" shall not be used.
**
** e) The origin of the SOFA components of your derived work must not
** be misrepresented; you must not claim that you wrote the
** original software, nor file a patent application for SOFA
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**
** f) These requirements must be reproduced intact in any source
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**
** 4. In any published work or commercial products which includes
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**
** 5. You shall not cause the SOFA software to be brought into
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**
** 6. The SOFA software is provided "as is" and the Board makes no
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**
** 7. The provision of any version of the SOFA software under the terms
** and conditions specified herein does not imply that future
** versions will also be made available under the same terms and
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**
** Correspondence concerning SOFA software should be addressed as
** follows:
**
** Internet email: sofa@rl.ac.uk
** Postal address: IAU SOFA Center
** Rutherford Appleton Laboratory
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** United Kingdom
**
**---------------------------------------------------------------------*/
}