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author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
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committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /math/slalib/ecmat.f | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/slalib/ecmat.f')
-rw-r--r-- | math/slalib/ecmat.f | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/math/slalib/ecmat.f b/math/slalib/ecmat.f new file mode 100644 index 00000000..8213dd8f --- /dev/null +++ b/math/slalib/ecmat.f @@ -0,0 +1,70 @@ + SUBROUTINE slECMA (DATE, RMAT) +*+ +* - - - - - - +* E C M A +* - - - - - - +* +* Form the equatorial to ecliptic rotation matrix - IAU 1980 theory +* (double precision) +* +* Given: +* DATE dp TDB (loosely ET) as Modified Julian Date +* (JD-2400000.5) +* Returned: +* RMAT dp(3,3) matrix +* +* Reference: +* Murray,C.A., Vectorial Astrometry, section 4.3. +* +* Note: +* The matrix is in the sense V(ecl) = RMAT * V(equ); the +* equator, equinox and ecliptic are mean of date. +* +* Called: slDEUL +* +* P.T.Wallace Starlink 23 August 1996 +* +* Copyright (C) 1996 Rutherford Appleton Laboratory +* +* License: +* 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 2 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 (see SLA_CONDITIONS); if not, write to the +* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +* Boston, MA 02110-1301 USA +* +* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. +*- + + IMPLICIT NONE + + DOUBLE PRECISION DATE,RMAT(3,3) + +* Arc seconds to radians + DOUBLE PRECISION AS2R + PARAMETER (AS2R=0.484813681109535994D-5) + + DOUBLE PRECISION T,EPS0 + + + +* Interval between basic epoch J2000.0 and current epoch (JC) + T = (DATE-51544.5D0)/36525D0 + +* Mean obliquity + EPS0 = AS2R* + : (84381.448D0+(-46.8150D0+(-0.00059D0+0.001813D0*T)*T)*T) + +* Matrix + CALL slDEUL('X',EPS0,0D0,0D0,RMAT) + + END |