DERKFS(3)

SYNOPSIS
SUBROUTINE DERKFS (F, NEQ, T, Y, TOUT, INFO, RTOL, ATOL, IDID, H, + TOLFAC, YP, F1, F2, F3, F4, F5, YS, TOLD, DTSIGN, U26, RER, + INIT, KSTEPS, KOP, IQUIT, STIFF, NONSTF, NTSTEP, NSTIFS, RPAR, + IPAR)

NAME
derkfs - Subsidiary to DERKF

LIBRARY
SLATEC

TYPE
SINGLE PRECISION (DERKFS-S, DRKFS-D)

AUTHOR
Watts, H. A., (SNLA)

DESCRIPTION
Fehlberg Fourth-Fifth order Runge-Kutta Method ********************************************************************** DERKFS integrates a system of first order ordinary differential equations as described in the comments for DERKF . The arrays YP,F1,F2,F3,F4,F5,and YS (of length at least NEQ) appear in the call list for variable dimensioning purposes. The variables H,TOLFAC,TOLD,DTSIGN,U26,RER,INIT,KSTEPS,KOP,IQUIT, STIFF,NONSTF,NTSTEP, and NSTIFS are used internally by the code and appear in the call list to eliminate local retention of variables between calls. Accordingly, these variables and the array YP should not be altered. Items of possible interest are H - An appropriate step size to be used for the next step TOLFAC - Factor of change in the tolerances YP - Derivative of solution vector at T KSTEPS - Counter on the number of steps attempted **********************************************************************

SEE ALSO
DERKF

ROUTINES CALLED
DEFEHL, HSTART, HVNRM, R1MACH, XERMSG

REVISION HISTORY (YYMMDD)
800501 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
891024 Changed references from VNORM to HVNRM. (WRB)
891024 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900328 Added TYPE section. (WRB)
900510 Convert XERRWV calls to XERMSG calls, replace GOTOs with IF-THEN-ELSEs. (RWC)
910722 Updated AUTHOR section. (ALS)