Add palEcleq

Author: timj

Makefile.am

@@ -58,6 +58,7 @@ palDt.c \
 palDtp2s.c \
 palDtps2c.c \
 palDtt.c \
+palEcleq.c \
 palEcmat.c \
 palEl2ue.c \
 palEpco.c \

palEcleq.c

@@ -0,0 +1,97 @@
+/*
+*+
+*  Name:
+*     palEcleq
+
+*  Purpose:
+*     Transform from ecliptic coordinates to J2000.0 equatorial coordinates
+
+*  Language:
+*     Starlink ANSI C
+
+*  Type of Module:
+*     Library routine
+
+*  Invocation:
+*     void palEcleq ( double dl, double db, double date,
+*                     double *dr, double *dd );
+
+*  Arguments:
+*     dl = double (Given)
+*        Ecliptic longitude (mean of date, IAU 1980 theory, radians)
+*     db = double (Given)
+*        Ecliptic latitude (mean of date, IAU 1980 theory, radians)
+*     date = double (Given)
+*        TT as Modified Julian Date (JD-2400000.5). The difference
+*        between TT and TDB is of the order of a millisecond or two
+*        (i.e. about 0.02 arc-seconds).
+*     dr = double * (Returned)
+*        J2000.0 mean RA (radians)
+*     dd = double * (Returned)
+*        J2000.0 mean Dec (Radians)
+
+*  Description:
+*     Transform from ecliptic coordinate to J2000.0 equatorial coordinates.
+
+*  Authors:
+*     PTW: Patrick T. Wallace
+*     TIMJ: Tim Jenness (Cornell University)
+*     {enter_new_authors_here}
+
+*  History:
+*     2014-11-18 (TIMJ):
+*        Initial version
+*        Adapted with permission from the Fortran SLALIB library.
+*     {enter_further_changes_here}
+
+*  Copyright:
+*     Copyright (C) 1995 Rutherford Appleton Laboratory
+*     Copyright (C) 2014 Cornell University
+*     All Rights Reserved.
+
+*  Licence:
+*     This program is free software; you can redistribute it and/or
+*     modify it under the terms of the GNU General Public License as
+*     published by the Free Software Foundation; either version 3 of
+*     the License, or (at your option) any later version.
+*
+*     This program is distributed in the hope that it will be
+*     useful, but WITHOUT ANY WARRANTY; without even the implied
+*     warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+*     PURPOSE. See the GNU General Public License for more details.
+*
+*     You should have received a copy of the GNU General Public License
+*     along with this program; if not, write to the Free Software
+*     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+*     MA 02110-1301, USA.
+
+*  Bugs:
+*     {note_any_bugs_here}
+*-
+*/
+
+#include "pal.h"
+#include "pal1sofa.h"
+
+void palEcleq ( double dl, double db, double date, double *dr, double *dd ) {
+  double v1[3], v2[3];
+  double rmat[3][3];
+
+  /* Spherical to Cartesian */
+  eraS2c( dl, db, v1 );
+
+  /* Ecliptic to equatorial */
+  palEcmat( date, rmat );
+  eraTrxp( rmat, v1, v2 );
+
+  /* Mean of date to J2000 */
+  palPrec( 2000.0, palEpj(date), rmat );
+  eraTrxp( rmat, v2, v1 );
+
+  /* Cartesian to spherical */
+  eraC2s( v1, dr, dd );
+
+  /* Express in conventional range */
+  *dr = eraAnp( *dr );
+  *dd = palDrange( *dd );
+}

palTest.c

@@ -1109,6 +1109,16 @@ static void t_vecmat( int * status ) {
 
 }
 
+static void t_ecleq( int *status ) {
+  double dr;
+  double dd;
+  palEcleq( 1.234, -0.123, 43210.0, &dr, &dd );
+  vvd( dr, 1.229910118208851, 1e-5, "palEcleq",
+       "RA", status );
+  vvd( dd, 0.2638461400411088, 1e-5, "palEcleq",
+       "Dec", status );
+}
+
 static void t_ecmat( int *status ) {
    double rmat[3][3];
    double expected[3][3] = {
@@ -1975,6 +1985,7 @@ int main (void) {
   t_intin(&status);
   t_prec(&status);
   t_preces(&status);
+  t_ecleq(&status);
   t_ecmat(&status);
   t_e2h(&status);
   t_map(&status);

sun267.tex

@@ -4054,6 +4054,48 @@ \subsection{More complex functions}
       }
    }
 }
+\sstroutine{
+   palEcleq
+}{
+   Transform from ecliptic coordinates to J2000.0 equatorial coordinates
+}{
+   \sstdescription{
+      Transform from ecliptic coordinate to J2000.0 equatorial coordinates.
+   }
+   \sstinvocation{
+      void palEcleq ( double dl, double db, double date,
+                      double $*$dr, double $*$dd );
+   }
+   \sstarguments{
+      \sstsubsection{
+         dl = double (Given)
+      }{
+         Ecliptic longitude (mean of date, IAU 1980 theory, radians)
+      }
+      \sstsubsection{
+         db = double (Given)
+      }{
+         Ecliptic latitude (mean of date, IAU 1980 theory, radians)
+      }
+      \sstsubsection{
+         date = double (Given)
+      }{
+         TT as Modified Julian Date (JD-2400000.5). The difference
+         between TT and TDB is of the order of a millisecond or two
+         (i.e. about 0.02 arc-seconds).
+      }
+      \sstsubsection{
+         dr = double $*$ (Returned)
+      }{
+         J2000.0 mean RA (radians)
+      }
+      \sstsubsection{
+         dd = double $*$ (Returned)
+      }{
+         J2000.0 mean Dec (Radians)
+      }
+   }
+}
 \sstroutine{
    palEcmat
 }{