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authorJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
committerJoe Hunkeler <jhunkeler@gmail.com>2015-08-11 16:51:37 -0400
commit40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch)
tree4464880c571602d54f6ae114729bf62a89518057 /math/slalib/ecmat.f
downloadiraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz
Repatch (from linux) of OSX IRAF
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+ 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