 
      SUBROUTINE SDNTL (EPS,F,FA,HMAX,HOLD,IMPL,JTASK,MATDIM,MAXORD,
     8   MINT,MITER,ML,MU,N,NDE,SAVE1,T,Y,YWT,H,MNTOLD,MTROLD,NFE,RC,YH,
     8   A,CONVRG,EL,IER,IPVT,NQ,NWAIT,RH,RMAX,SAVE2,TQ,TREND,ISWFLG)
C***BEGIN PROLOGUE  SDNTL
C***REFER TO  SDRIV3
C  Subroutine SDNTL is called to set parameters on the first call
C  to SDSTP, on an internal restart, or when the user has altered
C  MINT, MITER, and/or H.
C  On the first call, the order is set to 1 and the initial derivatives
C  are calculated.  RMAX is the maximum ratio by which H can be
C  increased in one step.  It is initially RMINIT to compensate
C  for the small initial H, but then is normally equal to RMNORM.
C  If a failure occurs (in corrector convergence or error test), RMAX
C  is set at RMFAIL for the next increase.
C  If the caller has changed MINT, or if JTASK = 0, SDCST is called
C  to set the coefficients of the method.  If the caller has changed H,
C  YH must be rescaled.  If H or MINT has been changed, NWAIT is
C  reset to NQ + 2 to prevent further increases in H for that many
C  steps.  Also, RC is reset.  RC is the ratio of new to old values of
C  the coefficient L(0)*H.  If the caller has changed MITER, RC is
C  set to 0 to force the partials to be updated, if partials are used.
C***ROUTINES CALLED  SDCST,SDSCL,SGEFA,SGESL,SGBFA,SGBSL,SNRM2
C***DATE WRITTEN   790601   (YYMMDD)
C***REVISION DATE  850320   (YYMMDD)
C***CATEGORY NO.  I1A2,I1A1B
C***AUTHOR  KAHANER, D. K., NATIONAL BUREAU OF STANDARDS,
C           SUTHERLAND, C. D., LOS ALAMOS NATIONAL LABORATORY
C***END PROLOGUE  SDNTL
 
 
