subroutine equecl_jd( jd, mode, equ, ecl )
!
!     Given a julian date (UT), and the position and velocity of an 
!     object in spherical coordinates in either the equatorial or 
!     ecliptic frame of reference, convert to the other frame.  If 
!     mode is positive, convert from equatorial to ecliptic; if mode
!     is negative, convert from ecliptic to equatorial.  The elements
!     of the 6-vectors equ and ecl are:
!
!        i   equ                    ecl
!
!        1   RA (rad, 0 to 2*pi)    L (rad, 0 to 2*pi)
!        2   Dec (rad, -pi to +pi)  B (rad, -pi to +pi)
!        3   R (AU)                 R (AU)
!        4   dRA/dt (rad/day)       dL/dt (rad/day)
!        5   dDec/dt (rad/day)      dB/dt (rad/day)
!        6   dR/dt (AU/day)         dR/dt (AU/day)
!
!     B. Knapp, 2002-08-30
!
C
C     RCS DATA
C     
C     $Header$
C     
C     $Log$
C
!
      implicit none
!
!     Input
      real*8 jd
      integer*4 mode
!
!     Input/Output (one each)
      real*8 equ(6), ecl(6)
!
!     External functions, subroutines
      real*8 ut2td, obliq
      external ut2td, obliq, equecl
!
!     Local variables
      real*8 t, eps
!
!     Get dynamic time (in Julian millenia since J2000)
      t = (ut2td(jd)-2451545.D0)/365250.D0
!
!     Get the obliquity of the ecliptic
      eps = obliq(t)
!
!     Perform the requested transformation
      call equecl(eps, mode, equ, ecl)
!
      return
      end