slaPrec -   
 SYNOPSYS 
 void  slaPrec(ep0, ep1, rmatp)
 PARAMETERS 
-   double  ep0 
-  
-   double  ep1 
-  
-   double ( *rmatp 
-  
 DESCRIPTION 
  Form the matrix of precession between two epochs (IAU 1976, FK5).
  (double precision)
 Given
     ep0    double         beginning epoch
     ep1    double         ending epoch
 Returned
     rmatp  double[3][3]   precession matrix
 Notes
  1)  The epochs are TDB (loosely ET) Julian epochs.
  2)  The matrix is in the sense   v(ep1)  =  rmatp * v(ep0) .
 References
     Lieske,J.H., 1979. Astron. Astrophys.,73,282.
          equations (6) & (7), p283.
     Kaplan,G.H., 1981. USNO circular no. 163, pa2.
 Called 
 slaDeuler
  Defined in slamac.h:  DAS2R
  P.T.Wallace   Starlink   31 October 1993
 SEE ALSO