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SUBROUTINE sla_EQECL (DR, DD, DATE, DL, DB)
*+
* - - - - - -
* E Q E C L
* - - - - - -
*
* Transformation from J2000.0 equatorial coordinates to
* ecliptic coordinates (double precision)
*
* Given:
* DR,DD dp J2000.0 mean RA,Dec (radians)
* DATE dp TDB (loosely ET) as Modified Julian Date
* (JD-2400000.5)
* Returned:
* DL,DB dp ecliptic longitude and latitude
* (mean of date, IAU 1980 theory, radians)
*
* Called:
* sla_DCS2C, sla_PREC, sla_EPJ, sla_DMXV, sla_ECMAT, sla_DCC2S,
* sla_DRANRM, sla_DRANGE
*
* P.T.Wallace Starlink March 1986
*
* Copyright (C) 1995 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
*-
IMPLICIT NONE
DOUBLE PRECISION DR,DD,DATE,DL,DB
DOUBLE PRECISION sla_EPJ,sla_DRANRM,sla_DRANGE
DOUBLE PRECISION RMAT(3,3),V1(3),V2(3)
* Spherical to Cartesian
CALL sla_DCS2C(DR,DD,V1)
* Mean J2000 to mean of date
CALL sla_PREC(2000D0,sla_EPJ(DATE),RMAT)
CALL sla_DMXV(RMAT,V1,V2)
* Equatorial to ecliptic
CALL sla_ECMAT(DATE,RMAT)
CALL sla_DMXV(RMAT,V2,V1)
* Cartesian to spherical
CALL sla_DCC2S(V1,DL,DB)
* Express in conventional ranges
DL=sla_DRANRM(DL)
DB=sla_DRANGE(DB)
END