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Diffstat (limited to 'ast/pal/palFk54z.c')
-rw-r--r-- | ast/pal/palFk54z.c | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/ast/pal/palFk54z.c b/ast/pal/palFk54z.c deleted file mode 100644 index b902b0d..0000000 --- a/ast/pal/palFk54z.c +++ /dev/null @@ -1,113 +0,0 @@ -/* -*+ -* Name: -* palFk54z - -* Purpose: -* Convert a J2000.0 FK5 star position to B1950.0 FK4 assuming -* zero proper motion and parallax. - -* Language: -* Starlink ANSI C - -* Type of Module: -* Library routine - -* Invocation: -* palFk54z( double r2000, double d2000, double bepoch, double *r1950, -* double *d1950, double *dr1950, double *dd1950 ) - -* Arguments: -* r2000 = double (Given) -* J2000.0 FK5 RA (radians). -* d2000 = double (Given) -* J2000.0 FK5 Dec (radians). -* bepoch = double (Given) -* Besselian epoch (e.g. 1950.0). -* r1950 = double * (Returned) -* B1950 FK4 RA (radians) at epoch "bepoch". -* d1950 = double * (Returned) -* B1950 FK4 Dec (radians) at epoch "bepoch". -* dr1950 = double * (Returned) -* B1950 FK4 proper motion (RA) (radians/trop.yr)). -* dr1950 = double * (Returned) -* B1950 FK4 proper motion (Dec) (radians/trop.yr)). - -* Description: -* This function converts star positions from the IAU 1976, -* FK5, Fricke system to the Bessel-Newcomb, FK4 system. - -* Notes: -* - The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt. -* - Conversion from Julian epoch 2000.0 to Besselian epoch 1950.0 -* only is provided for. Conversions involving other epochs will -* require use of the appropriate precession functions before and -* after this function is called. -* - The FK5 proper motions, the parallax and the radial velocity -* are presumed zero. -* - It is the intention that FK5 should be a close approximation -* to an inertial frame, so that distant objects have zero proper -* motion; such objects have (in general) non-zero proper motion -* in FK4, and this function returns those fictitious proper -* motions. -* - The position returned by this function is in the B1950 -* reference frame but at Besselian epoch BEPOCH. For comparison -* with catalogues the "bepoch" argument will frequently be 1950.0. - -* Authors: -* PTW: Pat Wallace (STFC) -* DSB: David Berry (JAC, Hawaii) -* {enter_new_authors_here} - -* History: -* 2012-02-13 (DSB): -* Initial version with documentation taken from Fortran SLA -* Adapted with permission from the Fortran SLALIB library. -* {enter_further_changes_here} - -* Copyright: -* Copyright (C) 1995 Rutherford Appleton Laboratory -* Copyright (C) 2012 Science and Technology Facilities Council. -* All Rights Reserved. - -* Licence: -* This program is free software: you can redistribute it and/or -* modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details. -* -* You should have received a copy of the GNU Lesser General -* License along with this program. If not, see -* <http://www.gnu.org/licenses/>. - -* Bugs: -* {note_any_bugs_here} -*- -*/ - -#include "pal.h" -#include "pal1sofa.h" - -void palFk54z( double r2000, double d2000, double bepoch, double *r1950, - double *d1950, double *dr1950, double *dd1950 ){ - -/* Local Variables: */ - double r, d, px, rv, y; - -/* FK5 equinox J2000 (any epoch) to FK4 equinox B1950 epoch B1950. */ - palFk524( r2000, d2000, 0.0, 0.0, 0.0, 0.0, &r, &d, dr1950, dd1950, - &px, &rv ); - -/* Fictitious proper motion to epoch "bepoch". */ - y = bepoch - 1950.0; - *r1950 = r + *dr1950*y; - *d1950 = d + *dd1950*y; - -} - |