DRKFS(3)

SYNOPSIS
SUBROUTINE DRKFS (DF, 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
drkfs - Subsidiary to DDERKF

LIBRARY
SLATEC

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

AUTHOR
Watts, H. A., (SNLA)

DESCRIPTION
Fehlberg Fourth-Fifth Order Runge-Kutta Method ********************************************************************** DRKFS integrates a system of first order ordinary differential equations as described in the comments for DDERKF . 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
DDERKF

ROUTINES CALLED
D1MACH, DFEHL, DHSTRT, DHVNRM, XERMSG

REVISION HISTORY (YYMMDD)
820301 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
891024 Changed references from DVNORM to DHVNRM. (WRB)
891214 Prologue converted to Version 4.0 format. (BAB)
900328 Added TYPE section. (WRB)
900510 Convert XERRWV calls to XERMSG calls, change GOTOs to IF-THEN-ELSEs. (RWC)
910722 Updated AUTHOR section. (ALS)