#include "sofam.h"

int iauGd2gc ( int n, double elong, double phi, double height,
               double xyz[3] )
/*
**  - - - - - - - - -
**   i a u G d 2 g c
**  - - - - - - - - -
**
**  Transform geodetic coordinates to geocentric using the specified
**  reference ellipsoid.
**
**  This function is part of the International Astronomical Union's
**  SOFA (Standards of Fundamental Astronomy) software collection.
**
**  Status:  canonical transformation.
**
**  Given:
**     n       int        ellipsoid identifier (Note 1)
**     elong   double     longitude (radians, east +ve)
**     phi     double     latitude (geodetic, radians, Note 3)
**     height  double     height above ellipsoid (geodetic, Notes 2,3)
**
**  Returned:
**     xyz     double[3]  geocentric vector (Note 2)
**
**  Returned (function value):
**             int        status:  0 = OK
**                                -1 = illegal identifier (Note 3)
**                                -2 = illegal case (Note 3)
**
**  Notes:
**
**  1) The identifier n is a number that specifies the choice of
**     reference ellipsoid.  The following are supported:
**
**        n    ellipsoid
**
**        1     WGS84
**        2     GRS80
**        3     WGS72
**
**     The n value has no significance outside the SOFA software.  For
**     convenience, symbols WGS84 etc. are defined in sofam.h.
**
**  2) The height (height, given) and the geocentric vector (xyz,
**     returned) are in meters.
**
**  3) No validation is performed on the arguments elong, phi and
**     height.  An error status -1 means that the identifier n is
**     illegal.  An error status -2 protects against cases that would
**     lead to arithmetic exceptions.  In all error cases, xyz is set
**     to zeros.
**
**  4) The inverse transformation is performed in the function iauGc2gd.
**
**  Called:
**     iauEform     Earth reference ellipsoids
**     iauGd2gce    geodetic to geocentric transformation, general
**     iauZp        zero p-vector
**
**  This revision:  2012 February 23
**
**  SOFA release 2012-03-01
**
**  Copyright (C) 2012 IAU SOFA Board.  See notes at end.
*/
{
   int j;
   double a, f;


/* Obtain reference ellipsoid parameters. */
   j = iauEform ( n, &a, &f );

/* If OK, transform longitude, geodetic latitude, height to x,y,z. */
   if ( j == 0 ) {
      j = iauGd2gce ( a, f, elong, phi, height, xyz );
      if ( j != 0 ) j = -2;
   }

/* Deal with any errors. */
   if ( j != 0 ) iauZp ( xyz );

/* Return the status. */
   return j;

/*----------------------------------------------------------------------
**
**  Copyright (C) 2012
**  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:  sofa@ukho.gov.uk
**      By post:   IAU SOFA Center
**                 HM Nautical Almanac Office
**                 UK Hydrographic Office
**                 Admiralty Way, Taunton
**                 Somerset, TA1 2DN
**                 United Kingdom
**
**--------------------------------------------------------------------*/

}
