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slalib/prenut.f

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+      SUBROUTINE sla_PRENUT (EPOCH, DATE, RMATPN)
+*+
+*     - - - - - - -
+*      P R E N U T
+*     - - - - - - -
+*
+*  Form the matrix of precession and nutation (SF2001)
+*  (double precision)
+*
+*  Given:
+*     EPOCH   dp         Julian Epoch for mean coordinates
+*     DATE    dp         Modified Julian Date (JD-2400000.5)
+*                        for true coordinates
+*
+*  Returned:
+*     RMATPN  dp(3,3)    combined precession/nutation matrix
+*
+*  Called:  sla_PREC, sla_EPJ, sla_NUT, sla_DMXM
+*
+*  Notes:
+*
+*  1)  The epoch and date are TDB (loosely ET).  TT will do, or even
+*      UTC.
+*
+*  2)  The matrix is in the sense   V(true) = RMATPN * V(mean)
+*
+*  Last revision:   3 December 2005
+*
+*  Copyright P.T.Wallace.  All rights reserved.
+*
+*  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., 59 Temple Place, Suite 330, 
+*    Boston, MA  02111-1307  USA
+*
+*-
+
+      IMPLICIT NONE
+
+      DOUBLE PRECISION EPOCH,DATE,RMATPN(3,3)
+
+      DOUBLE PRECISION RMATP(3,3),RMATN(3,3),sla_EPJ
+
+
+
+*  Precession
+      CALL sla_PREC(EPOCH,sla_EPJ(DATE),RMATP)
+
+*  Nutation
+      CALL sla_NUT(DATE,RMATN)
+
+*  Combine the matrices:  PN = N x P
+      CALL sla_DMXM(RMATN,RMATP,RMATPN)
+
+      END