DDNTL(3)

SYNOPSIS
SUBROUTINE DDNTL (EPS, F, FA, HMAX, HOLD, IMPL, JTASK, MATDIM, 8 MAXORD, MINT, MITER, ML, MU, N, NDE, SAVE1, T, UROUND, USERS, 8 Y, YWT, H, MNTOLD, MTROLD, NFE, RC, YH, A, CONVRG, EL, FAC, 8 IER, IPVT, NQ, NWAIT, RH, RMAX, SAVE2, TQ, TREND, ISWFLG, 8 JSTATE)

NAME
ddntl - Subroutine DDNTL is called to set parameters on the first call to DDSTP, on an internal restart, or when the user has altered MINT, MITER, and/or H.

LIBRARY
SLATEC (SDRIVE)

TYPE
DOUBLE PRECISION (SDNTL-S, DDNTL-D, CDNTL-C)

AUTHOR
Kahaner, D. K., (NIST) National Institute of Standards and Technology Gaithersburg, MD 20899 Sutherland, C. D., (LANL) Mail Stop D466 Los Alamos National Laboratory Los Alamos, NM 87545

DESCRIPTION
On the first call, the order is set to 1 and the initial derivatives are calculated. RMAX is the maximum ratio by which H can be increased in one step. It is initially RMINIT to compensate for the small initial H, but then is normally equal to RMNORM. If a failure occurs (in corrector convergence or error test), RMAX is set at RMFAIL for the next increase. If the caller has changed MINT, or if JTASK = 0, DDCST is called to set the coefficients of the method. If the caller has changed H, YH must be rescaled. If H or MINT has been changed, NWAIT is reset to NQ + 2 to prevent further increases in H for that many steps. Also, RC is reset. RC is the ratio of new to old values of the coefficient L(0)*H. If the caller has changed MITER, RC is set to 0 to force the partials to be updated, if partials are used.

ROUTINES CALLED
DDCST, DDSCL, DGBFA, DGBSL, DGEFA, DGESL, DNRM2

REVISION HISTORY (YYMMDD)
790601 DATE WRITTEN
900329 Initial submission to SLATEC.