Exemple #1
0
void
palDeuler( const char *order, double phi, double theta, double psi,
                 double rmat[3][3] ) {
  int i = 0;
  double rotations[3];

  /* Initialise rmat */
  iauIr( rmat );

  /* copy the rotations into an array */
  rotations[0] = phi;
  rotations[1] = theta;
  rotations[2] = psi;

  /* maximum three rotations */
  while (i < 3 && order[i] != '\0') {

    switch (order[i]) {
    case 'X':
    case 'x':
    case '1':
      iauRx( rotations[i], rmat );
      break;

    case 'Y':
    case 'y':
    case '2':
      iauRy( rotations[i], rmat );
      break;

    case 'Z':
    case 'z':
    case '3':
      iauRz( rotations[i], rmat );
      break;

    default:
      /* break out the loop if we do not recognize something */
      i = 3;

    }

    /* Go to the next position */
    i++;
  }

  return;
}
void iauPmat76(double date1, double date2, double rmatp[3][3])
/*
**  - - - - - - - - - -
**   i a u P m a t 7 6
**  - - - - - - - - - -
**
**  Precession matrix from J2000.0 to a specified date, IAU 1976 model.
**
**  This function is part of the International Astronomical Union's
**  SOFA (Standards Of Fundamental Astronomy) software collection.
**
**  Status:  support function.
**
**  Given:
**     date1,date2 double       ending date, TT (Note 1)
**
**  Returned:
**     rmatp       double[3][3] precession matrix, J2000.0 -> date1+date2
**
**  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 operates in the sense V(date) = RMATP * V(J2000),
**     where the p-vector V(J2000) is with respect to the mean
**     equatorial triad of epoch J2000.0 and the p-vector V(date)
**     is with respect to the mean equatorial triad of the given
**     date.
**
**  3) Though the matrix method itself is rigorous, the precession
**     angles are expressed through canonical polynomials which are
**     valid only for a limited time span.  In addition, the IAU 1976
**     precession rate is known to be imperfect.  The absolute accuracy
**     of the present formulation is better than 0.1 arcsec from
**     1960AD to 2040AD, better than 1 arcsec from 1640AD to 2360AD,
**     and remains below 3 arcsec for the whole of the period
**     500BC to 3000AD.  The errors exceed 10 arcsec outside the
**     range 1200BC to 3900AD, exceed 100 arcsec outside 4200BC to
**     5600AD and exceed 1000 arcsec outside 6800BC to 8200AD.
**
**  Called:
**     iauPrec76    accumulated precession angles, IAU 1976
**     iauIr        initialize r-matrix to identity
**     iauRz        rotate around Z-axis
**     iauRy        rotate around Y-axis
**     iauCr        copy r-matrix
**
**  References:
**
**     Lieske, J.H., 1979, Astron.Astrophys. 73, 282.
**      equations (6) & (7), p283.
**
**     Kaplan,G.H., 1981. USNO circular no. 163, pA2.
**
**  This revision:  2013 June 18
**
**  SOFA release 2016-05-03
**
**  Copyright (C) 2016 IAU SOFA Board.  See notes at end.
*/
{
   double zeta, z, theta, wmat[3][3];


/* Precession Euler angles, J2000.0 to specified date. */
   iauPrec76(DJ00, 0.0, date1, date2, &zeta, &z, &theta);

/* Form the rotation matrix. */
   iauIr(  wmat);
   iauRz( -zeta, wmat);
   iauRy(  theta, wmat);
   iauRz( -z, wmat);
   iauCr( wmat, rmatp);

   return;

/*----------------------------------------------------------------------
**
**  Copyright (C) 2016
**  Standards Of Fundamental Astronomy Board
**  of the International Astronomical Union.
**
**  =====================
**  SOFA Software License
**  =====================
**
**  NOTICE TO USER:
**
**  BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
**  CONDITIONS WHICH APPLY TO ITS USE.
**
**  1. The Software is owned by the IAU SOFA Board ("SOFA").
**
**  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 distribute SOFA source code to others,
**     and use and adapt its code and algorithms in your own software,
**     on a world-wide, royalty-free basis.  That portion of your
**     distribution that does not consist of intact and unchanged copies
**     of SOFA source code files is a "derived work" that must comply
**     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 itself constitute software provided by and/or
**        endorsed by SOFA.
**
**     b) The source code of your derived work must contain descriptions
**        of how the derived work is based upon, contains and/or differs
**        from the original SOFA software.
**
**     c) The names of all routines in your derived work shall not
**        include the prefix "iau" or "sofa" or trivial modifications
**        thereof such as changes of case.
**
**     d) 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
**        software or algorithms embedded in the SOFA software.
**
**     e) These requirements must be reproduced intact in any source
**        distribution and shall apply to anyone to whom you have
**        granted a further right to modify the source code of your
**        derived work.
**
**     Note that, as originally distributed, the SOFA software is
**     intended to be a definitive implementation of the IAU standards,
**     and consequently third-party modifications are discouraged.  All
**     variations, no matter how minor, must be explicitly marked as
**     such, as explained above.
**
**  4. You shall not cause the SOFA software to be brought into
**     disrepute, either by misuse, or use for inappropriate tasks, or
**     by inappropriate modification.
**
**  5. The SOFA software is provided "as is" and SOFA makes no warranty
**     as to its use or performance.   SOFA does not and cannot warrant
**     the performance or results which the user may obtain by using the
**     SOFA software.  SOFA makes no warranties, express or implied, as
**     to non-infringement of third party rights, merchantability, or
**     fitness for any particular purpose.  In no event will SOFA be
**     liable to the user for any consequential, incidental, or special
**     damages, including any lost profits or lost savings, even if a
**     SOFA representative has been advised of such damages, or for any
**     claim by any third party.
**
**  6. 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
**     conditions.
*
**  In any published work or commercial product which uses the SOFA
**  software directly, acknowledgement (see www.iausofa.org) is
**  appreciated.
**
**  Correspondence concerning SOFA software should be addressed as
**  follows:
**
**      By email:  [email protected]
**      By post:   IAU SOFA Center
**                 HM Nautical Almanac Office
**                 UK Hydrographic Office
**                 Admiralty Way, Taunton
**                 Somerset, TA1 2DN
**                 United Kingdom
**
**--------------------------------------------------------------------*/
}
void iauC2ixys(double x, double y, double s, double rc2i[3][3])
/*
**  - - - - - - - - - -
**   i a u C 2 i x y s
**  - - - - - - - - - -
**
**  Form the celestial to intermediate-frame-of-date matrix given the CIP
**  X,Y and the CIO locator s.
**
**  This function is part of the International Astronomical Union's
**  SOFA (Standards Of Fundamental Astronomy) software collection.
**
**  Status:  support function.
**
**  Given:
**     x,y      double         Celestial Intermediate Pole (Note 1)
**     s        double         the CIO locator s (Note 2)
**
**  Returned:
**     rc2i     double[3][3]   celestial-to-intermediate matrix (Note 3)
**
**  Notes:
**
**  1) The Celestial Intermediate Pole coordinates are the x,y
**     components of the unit vector in the Geocentric Celestial
**     Reference System.
**
**  2) The CIO locator s (in radians) positions the Celestial
**     Intermediate Origin on the equator of the CIP.
**
**  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.
**
**  Called:
**     iauIr        initialize r-matrix to identity
**     iauRz        rotate around Z-axis
**     iauRy        rotate around Y-axis
**
**  Reference:
**
**     McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
**     IERS Technical Note No. 32, BKG (2004)
**
**  This revision:  2014 November 7
**
**  SOFA release 2016-05-03
**
**  Copyright (C) 2016 IAU SOFA Board.  See notes at end.
*/
{
   double r2, e, d;


/* Obtain the spherical angles E and d. */
   r2 = x*x + y*y;
   e = (r2 > 0.0) ? atan2(y, x) : 0.0;
   d = atan(sqrt(r2 / (1.0 - r2)));

/* Form the matrix. */
   iauIr(rc2i);
   iauRz(e, rc2i);
   iauRy(d, rc2i);
   iauRz(-(e+s), rc2i);

   return;

/*----------------------------------------------------------------------
**
**  Copyright (C) 2016
**  Standards Of Fundamental Astronomy Board
**  of the International Astronomical Union.
**
**  =====================
**  SOFA Software License
**  =====================
**
**  NOTICE TO USER:
**
**  BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
**  CONDITIONS WHICH APPLY TO ITS USE.
**
**  1. The Software is owned by the IAU SOFA Board ("SOFA").
**
**  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 distribute SOFA source code to others,
**     and use and adapt its code and algorithms in your own software,
**     on a world-wide, royalty-free basis.  That portion of your
**     distribution that does not consist of intact and unchanged copies
**     of SOFA source code files is a "derived work" that must comply
**     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 itself constitute software provided by and/or
**        endorsed by SOFA.
**
**     b) The source code of your derived work must contain descriptions
**        of how the derived work is based upon, contains and/or differs
**        from the original SOFA software.
**
**     c) The names of all routines in your derived work shall not
**        include the prefix "iau" or "sofa" or trivial modifications
**        thereof such as changes of case.
**
**     d) 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
**        software or algorithms embedded in the SOFA software.
**
**     e) These requirements must be reproduced intact in any source
**        distribution and shall apply to anyone to whom you have
**        granted a further right to modify the source code of your
**        derived work.
**
**     Note that, as originally distributed, the SOFA software is
**     intended to be a definitive implementation of the IAU standards,
**     and consequently third-party modifications are discouraged.  All
**     variations, no matter how minor, must be explicitly marked as
**     such, as explained above.
**
**  4. You shall not cause the SOFA software to be brought into
**     disrepute, either by misuse, or use for inappropriate tasks, or
**     by inappropriate modification.
**
**  5. The SOFA software is provided "as is" and SOFA makes no warranty
**     as to its use or performance.   SOFA does not and cannot warrant
**     the performance or results which the user may obtain by using the
**     SOFA software.  SOFA makes no warranties, express or implied, as
**     to non-infringement of third party rights, merchantability, or
**     fitness for any particular purpose.  In no event will SOFA be
**     liable to the user for any consequential, incidental, or special
**     damages, including any lost profits or lost savings, even if a
**     SOFA representative has been advised of such damages, or for any
**     claim by any third party.
**
**  6. 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
**     conditions.
*
**  In any published work or commercial product which uses the SOFA
**  software directly, acknowledgement (see www.iausofa.org) is
**  appreciated.
**
**  Correspondence concerning SOFA software should be addressed as
**  follows:
**
**      By email:  [email protected]
**      By post:   IAU SOFA Center
**                 HM Nautical Almanac Office
**                 UK Hydrographic Office
**                 Admiralty Way, Taunton
**                 Somerset, TA1 2DN
**                 United Kingdom
**
**--------------------------------------------------------------------*/
}
Exemple #4
0
void iauBp00(double date1, double date2,
             double rb[3][3], double rp[3][3], double rbp[3][3])
/*
**  - - - - - - - -
**   i a u B p 0 0
**  - - - - - - - -
**
**  Frame bias and precession, IAU 2000.
**
**  Status:  canonical model.
**
**  Given:
**     date1,date2  double         TT as a 2-part Julian Date (Note 1)
**
**  Returned:
**     rb           double[3][3]   frame bias matrix (Note 2)
**     rp           double[3][3]   precession matrix (Note 3)
**     rbp          double[3][3]   bias-precession matrix (Note 4)
**
**  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 rb transforms vectors from GCRS to mean J2000.0 by
**     applying frame bias.
**
**  3) The matrix rp transforms vectors from J2000.0 mean equator and
**     equinox to mean equator and equinox of date by applying
**     precession.
**
**  4) 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.
**
**  5) It is permissible to re-use the same array in the returned
**     arguments.  The arrays are filled in the order given.
**
**  Called:
**     iauBi00      frame bias components, IAU 2000
**     iauPr00      IAU 2000 precession adjustments
**     iauIr        initialize r-matrix to identity
**     iauRx        rotate around X-axis
**     iauRy        rotate around Y-axis
**     iauRz        rotate around Z-axis
**     iauCr        copy r-matrix
**     iauRxr       product of two r-matrices
**
**  Reference:
**     "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.
**
**  This revision:  2010 January 18
**
**  Original version 2012-03-01
**
**  Copyright (C) 2013 Naoki Arita.  See notes at end.
*/
{
/* J2000.0 obliquity (Lieske et al. 1977) */
   const double EPS0 = 84381.448 * DAS2R;

   double t, dpsibi, depsbi;
   double dra0, psia77, oma77, chia, dpsipr, depspr, psia, oma,
          rbw[3][3];


/* Interval between fundamental epoch J2000.0 and current date (JC). */
   t = ((date1 - DJ00) + date2) / DJC;

/* Frame bias. */
   iauBi00(&dpsibi, &depsbi, &dra0);

/* Precession angles (Lieske et al. 1977) */
   psia77 = (5038.7784 + (-1.07259 + (-0.001147) * t) * t) * t * DAS2R;
   oma77  =       EPS0 + ((0.05127 + (-0.007726) * t) * t) * t * DAS2R;
   chia   = (  10.5526 + (-2.38064 + (-0.001125) * t) * t) * t * DAS2R;

/* Apply IAU 2000 precession corrections. */
   iauPr00(date1, date2, &dpsipr,  &depspr);
   psia = psia77 + dpsipr;
   oma  = oma77  + depspr;

/* Frame bias matrix: GCRS to J2000.0. */
   iauIr(rbw);
   iauRz(dra0, rbw);
   iauRy(dpsibi * sin(EPS0), rbw);
   iauRx(-depsbi, rbw);
   iauCr(rbw, rb);

/* Precession matrix: J2000.0 to mean of date. */
   iauIr(rp);
   iauRx(EPS0,  rp);
   iauRz(-psia, rp);
   iauRx(-oma,  rp);
   iauRz(chia,  rp);

/* Bias-precession matrix: GCRS to mean of date. */
   iauRxr(rp, rbw, rbp);

   return;

/*----------------------------------------------------------------------
**
**  Celes is a wrapper of the SOFA Library for Ruby.
**
**  This file is redistributed and relicensed in accordance with 
**  the SOFA Software License (http://www.iausofa.org/tandc.html).
**
**  The original library is available from IAU Standards of
**  Fundamental Astronomy (http://www.iausofa.org/).
**
**
**
**
**
**  Copyright (C) 2013, Naoki Arita
**  All rights reserved.
**
**  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.
**
**--------------------------------------------------------------------*/
}
Exemple #5
0
void iauBp00(double date1, double date2,
             double rb[3][3], double rp[3][3], double rbp[3][3])
/*
**  - - - - - - - -
**   i a u B p 0 0
**  - - - - - - - -
**
**  Frame bias and precession, IAU 2000.
**
**  This function is part of the International Astronomical Union's
**  SOFA (Standards Of Fundamental Astronomy) software collection.
**
**  Status:  canonical model.
**
**  Given:
**     date1,date2  double         TT as a 2-part Julian Date (Note 1)
**
**  Returned:
**     rb           double[3][3]   frame bias matrix (Note 2)
**     rp           double[3][3]   precession matrix (Note 3)
**     rbp          double[3][3]   bias-precession matrix (Note 4)
**
**  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 rb transforms vectors from GCRS to mean J2000.0 by
**     applying frame bias.
**
**  3) The matrix rp transforms vectors from J2000.0 mean equator and
**     equinox to mean equator and equinox of date by applying
**     precession.
**
**  4) 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.
**
**  5) It is permissible to re-use the same array in the returned
**     arguments.  The arrays are filled in the order given.
**
**  Called:
**     iauBi00      frame bias components, IAU 2000
**     iauPr00      IAU 2000 precession adjustments
**     iauIr        initialize r-matrix to identity
**     iauRx        rotate around X-axis
**     iauRy        rotate around Y-axis
**     iauRz        rotate around Z-axis
**     iauCr        copy r-matrix
**     iauRxr       product of two r-matrices
**
**  Reference:
**     "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.
**
**  This revision:  2010 January 18
**
**  SOFA release 2010-12-01
**
**  Copyright (C) 2010 IAU SOFA Board.  See notes at end.
*/
{
/* J2000.0 obliquity (Lieske et al. 1977) */
   const double EPS0 = 84381.448 * DAS2R;

   double t, dpsibi, depsbi;
   double dra0, psia77, oma77, chia, dpsipr, depspr, psia, oma,
          rbw[3][3];


/* Interval between fundamental epoch J2000.0 and current date (JC). */
   t = ((date1 - DJ00) + date2) / DJC;

/* Frame bias. */
   iauBi00(&dpsibi, &depsbi, &dra0);

/* Precession angles (Lieske et al. 1977) */
   psia77 = (5038.7784 + (-1.07259 + (-0.001147) * t) * t) * t * DAS2R;
   oma77  =       EPS0 + ((0.05127 + (-0.007726) * t) * t) * t * DAS2R;
   chia   = (  10.5526 + (-2.38064 + (-0.001125) * t) * t) * t * DAS2R;

/* Apply IAU 2000 precession corrections. */
   iauPr00(date1, date2, &dpsipr,  &depspr);
   psia = psia77 + dpsipr;
   oma  = oma77  + depspr;

/* Frame bias matrix: GCRS to J2000.0. */
   iauIr(rbw);
   iauRz(dra0, rbw);
   iauRy(dpsibi * sin(EPS0), rbw);
   iauRx(-depsbi, rbw);
   iauCr(rbw, rb);

/* Precession matrix: J2000.0 to mean of date. */
   iauIr(rp);
   iauRx(EPS0,  rp);
   iauRz(-psia, rp);
   iauRx(-oma,  rp);
   iauRz(chia,  rp);

/* Bias-precession matrix: GCRS to mean of date. */
   iauRxr(rp, rbw, rbp);

   return;

/*----------------------------------------------------------------------
**
**  Copyright (C) 2010
**  Standards Of Fundamental Astronomy 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 Board ("SOFA").
**
**  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 distribute SOFA source code to others,
**     and use and adapt its code and algorithms in your own software,
**     on a world-wide, royalty-free basis.  That portion of your
**     distribution that does not consist of intact and unchanged copies
**     of SOFA source code files is a "derived work" that must comply
**     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 itself constitute software provided by and/or
**        endorsed by SOFA.
**
**     b) The source code of your derived work must contain descriptions
**        of how the derived work is based upon, contains and/or differs
**        from the original SOFA software.
**
**     c) The name(s) of all routine(s) in your derived work shall not
**        include the prefix "iau".
**
**     d) 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
**        software or algorithms embedded in the SOFA software.
**
**     e) These requirements must be reproduced intact in any source
**        distribution and shall apply to anyone to whom you have
**        granted a further right to modify the source code of your
**        derived work.
**
**     Note that, as originally distributed, the SOFA software is
**     intended to be a definitive implementation of the IAU standards,
**     and consequently third-party modifications are discouraged.  All
**     variations, no matter how minor, must be explicitly marked as
**     such, as explained above.
**
**  4. In any published work or commercial products which includes
**     results achieved by using the SOFA software, you shall
**     acknowledge that the SOFA software was used in obtaining those
**     results.
**
**  5. You shall not cause the SOFA software to be brought into
**     disrepute, either by misuse, or use for inappropriate tasks, or
**     by inappropriate modification.
**
**  6. The SOFA software is provided "as is" and SOFA makes no warranty
**     as to its use or performance.   SOFA does not and cannot warrant
**     the performance or results which the user may obtain by using the
**     SOFA software.  SOFA makes no warranties, express or implied, as
**     to non-infringement of third party rights, merchantability, or
**     fitness for any particular purpose.  In no event will SOFA be
**     liable to the user for any consequential, incidental, or special
**     damages, including any lost profits or lost savings, even if a
**     SOFA representative has been advised of such damages, or for any
**     claim by any third party.
**
**  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
**     conditions.
**
**  Correspondence concerning SOFA software should be addressed as
**  follows:
**
**      By email:  [email protected]
**      By post:   IAU SOFA Center
**                 HM Nautical Almanac Office
**                 UK Hydrographic Office
**                 Admiralty Way, Taunton
**                 Somerset, TA1 2DN
**                 United Kingdom
**
**--------------------------------------------------------------------*/
}
void iauPom00(double xp, double yp, double sp, double rpom[3][3])
/*
**  - - - - - - - - - -
**   i a u P o m 0 0
**  - - - - - - - - - -
**
**  Form the matrix of polar motion for a given date, IAU 2000.
**
**  This function is part of the International Astronomical Union's
**  SOFA (Standards Of Fundamental Astronomy) software collection.
**
**  Status:  support function.
**
**  Given:
**     xp,yp    double    coordinates of the pole (radians, Note 1)
**     sp       double    the TIO locator s' (radians, Note 2)
**
**  Returned:
**     rpom     double[3][3]   polar-motion matrix (Note 3)
**
**  Notes:
**
**  1) The arguments xp and yp are the coordinates (in radians) of the
**     Celestial Intermediate Pole with respect to the International
**     Terrestrial Reference System (see IERS Conventions 2003),
**     measured along the meridians to 0 and 90 deg west respectively.
**
**  2) The argument sp is the TIO locator s', in radians, which
**     positions the Terrestrial Intermediate Origin on the equator.  It
**     is obtained from polar motion observations by numerical
**     integration, and so is in essence unpredictable.  However, it is
**     dominated by a secular drift of about 47 microarcseconds per
**     century, and so can be taken into account by using s' = -47*t,
**     where t is centuries since J2000.0.  The function iauSp00
**     implements this approximation.
**
**  3) The matrix operates in the sense V(TRS) = rpom * V(CIP), meaning
**     that it is the final rotation when computing the pointing
**     direction to a celestial source.
**
**  Called:
**     iauIr        initialize r-matrix to identity
**     iauRz        rotate around Z-axis
**     iauRy        rotate around Y-axis
**     iauRx        rotate around X-axis
**
**  Reference:
**
**     McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
**     IERS Technical Note No. 32, BKG (2004)
**
**  This revision:  2013 June 18
**
**  SOFA release 2016-05-03
**
**  Copyright (C) 2016 IAU SOFA Board.  See notes at end.
*/
{

/* Construct the matrix. */
   iauIr(rpom);
   iauRz(sp, rpom);
   iauRy(-xp, rpom);
   iauRx(-yp, rpom);

   return;

/*----------------------------------------------------------------------
**
**  Copyright (C) 2016
**  Standards Of Fundamental Astronomy Board
**  of the International Astronomical Union.
**
**  =====================
**  SOFA Software License
**  =====================
**
**  NOTICE TO USER:
**
**  BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
**  CONDITIONS WHICH APPLY TO ITS USE.
**
**  1. The Software is owned by the IAU SOFA Board ("SOFA").
**
**  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 distribute SOFA source code to others,
**     and use and adapt its code and algorithms in your own software,
**     on a world-wide, royalty-free basis.  That portion of your
**     distribution that does not consist of intact and unchanged copies
**     of SOFA source code files is a "derived work" that must comply
**     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 itself constitute software provided by and/or
**        endorsed by SOFA.
**
**     b) The source code of your derived work must contain descriptions
**        of how the derived work is based upon, contains and/or differs
**        from the original SOFA software.
**
**     c) The names of all routines in your derived work shall not
**        include the prefix "iau" or "sofa" or trivial modifications
**        thereof such as changes of case.
**
**     d) 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
**        software or algorithms embedded in the SOFA software.
**
**     e) These requirements must be reproduced intact in any source
**        distribution and shall apply to anyone to whom you have
**        granted a further right to modify the source code of your
**        derived work.
**
**     Note that, as originally distributed, the SOFA software is
**     intended to be a definitive implementation of the IAU standards,
**     and consequently third-party modifications are discouraged.  All
**     variations, no matter how minor, must be explicitly marked as
**     such, as explained above.
**
**  4. You shall not cause the SOFA software to be brought into
**     disrepute, either by misuse, or use for inappropriate tasks, or
**     by inappropriate modification.
**
**  5. The SOFA software is provided "as is" and SOFA makes no warranty
**     as to its use or performance.   SOFA does not and cannot warrant
**     the performance or results which the user may obtain by using the
**     SOFA software.  SOFA makes no warranties, express or implied, as
**     to non-infringement of third party rights, merchantability, or
**     fitness for any particular purpose.  In no event will SOFA be
**     liable to the user for any consequential, incidental, or special
**     damages, including any lost profits or lost savings, even if a
**     SOFA representative has been advised of such damages, or for any
**     claim by any third party.
**
**  6. 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
**     conditions.
*
**  In any published work or commercial product which uses the SOFA
**  software directly, acknowledgement (see www.iausofa.org) is
**  appreciated.
**
**  Correspondence concerning SOFA software should be addressed as
**  follows:
**
**      By email:  [email protected]
**      By post:   IAU SOFA Center
**                 HM Nautical Almanac Office
**                 UK Hydrographic Office
**                 Admiralty Way, Taunton
**                 Somerset, TA1 2DN
**                 United Kingdom
**
**--------------------------------------------------------------------*/
}