DOPRI5Run Method

public void Run(
	int N,
	IFAREN FCN,
	ref double X,
	ref double[] Y,
	int offset_y,
	double XEND,
	double[] RTOL,
	int offset_rtol,
	double[] ATOL,
	int offset_atol,
	int ITOL,
	ISOLOUT SOLOUT,
	int IOUT,
	ref double[] WORK,
	int offset_work,
	int LWORK,
	ref int[] IWORK,
	int offset_iwork,
	int LIWORK,
	double[] RPAR,
	int offset_rpar,
	int[] IPAR,
	int offset_ipar,
	ref int IDID
)

Public Sub Run ( 
	N As Integer,
	FCN As IFAREN,
	ByRef X As Double,
	ByRef Y As Double(),
	offset_y As Integer,
	XEND As Double,
	RTOL As Double(),
	offset_rtol As Integer,
	ATOL As Double(),
	offset_atol As Integer,
	ITOL As Integer,
	SOLOUT As ISOLOUT,
	IOUT As Integer,
	ByRef WORK As Double(),
	offset_work As Integer,
	LWORK As Integer,
	ByRef IWORK As Integer(),
	offset_iwork As Integer,
	LIWORK As Integer,
	RPAR As Double(),
	offset_rpar As Integer,
	IPAR As Integer(),
	offset_ipar As Integer,
	ByRef IDID As Integer
)

Parameters

N  Int32

DIMENSION OF THE SYSTEM

FCN  IFAREN

NAME (EXTERNAL) OF SUBROUTINE COMPUTING THE VALUE OF F(X,Y): SUBROUTINE FCN(N,X,Y,F,RPAR,IPAR) DOUBLE PRECISION X,Y(N),F(N) F(1)=... ETC.

X  Double

INITIAL X-VALUE

Y  Double

 

offset_y  Int32

 

XEND  Double

FINAL X-VALUE (XEND-X MAY BE POSITIVE OR NEGATIVE)

RTOL  Double

 

offset_rtol  Int32

 

ATOL  Double

 

offset_atol  Int32

 

ITOL  Int32

SWITCH FOR RTOL AND ATOL: ITOL=0: BOTH RTOL AND ATOL ARE SCALARS. THE CODE KEEPS, ROUGHLY, THE LOCAL ERROR OF Y(I) BELOW RTOL*ABS(Y(I))+ATOL ITOL=1: BOTH RTOL AND ATOL ARE VECTORS. THE CODE KEEPS THE LOCAL ERROR OF Y(I) BELOW RTOL(I)*ABS(Y(I))+ATOL(I).

SOLOUT  ISOLOUT

NAME (EXTERNAL) OF SUBROUTINE PROVIDING THE NUMERICAL SOLUTION DURING INTEGRATION. IF IOUT.GE.1, IT IS CALLED AFTER EVERY SUCCESSFUL STEP. SUPPLY A DUMMY SUBROUTINE IF IOUT=0. IT MUST HAVE THE FORM SUBROUTINE SOLOUT (NR,XOLD,X,Y,N,CON,ICOMP,ND, RPAR,IPAR,IRTRN) DIMENSION Y(N),CON(5*ND),ICOMP(ND) .... SOLOUT FURNISHES THE SOLUTION "Y" AT THE NR-TH GRID-POINT "X" (THEREBY THE INITIAL VALUE IS THE FIRST GRID-POINT). "XOLD" IS THE PRECEEDING GRID-POINT. "IRTRN" SERVES TO INTERRUPT THE INTEGRATION. IF IRTRN IS SET .LT.0, DOPRI5 WILL RETURN TO THE CALLING PROGRAM. IF THE NUMERICAL SOLUTION IS ALTERED IN SOLOUT, SET IRTRN = 2 ----- CONTINUOUS OUTPUT: ----- DURING CALLS TO "SOLOUT", A CONTINUOUS SOLUTION FOR THE INTERVAL [XOLD,X] IS AVAILABLE THROUGH THE FUNCTION .GT..GT..GT. CONTD5(I,S,CON,ICOMP,ND) .LT..LT..LT. WHICH PROVIDES AN APPROXIMATION TO THE I-TH COMPONENT OF THE SOLUTION AT THE POINT S. THE VALUE S SHOULD LIE IN THE INTERVAL [XOLD,X].

IOUT  Int32

SWITCH FOR CALLING THE SUBROUTINE SOLOUT: IOUT=0: SUBROUTINE IS NEVER CALLED IOUT=1: SUBROUTINE IS USED FOR OUTPUT. IOUT=2: DENSE OUTPUT IS PERFORMED IN SOLOUT (IN THIS CASE WORK(5) MUST BE SPECIFIED)

WORK  Double

ARRAY OF WORKING SPACE OF LENGTH "LWORK". WORK(1),...,WORK(20) SERVE AS PARAMETERS FOR THE CODE. FOR STANDARD USE, SET THEM TO ZERO BEFORE CALLING. "LWORK" MUST BE AT LEAST 8*N+5*NRDENS+21 WHERE NRDENS = IWORK(5)

offset_work  Int32

 

LWORK  Int32

DECLARED LENGHT OF ARRAY "WORK".

IWORK  Int32

INTEGER WORKING SPACE OF LENGHT "LIWORK". IWORK(1),...,IWORK(20) SERVE AS PARAMETERS FOR THE CODE. FOR STANDARD USE, SET THEM TO ZERO BEFORE CALLING. "LIWORK" MUST BE AT LEAST NRDENS+21 .

offset_iwork  Int32

 

LIWORK  Int32

DECLARED LENGHT OF ARRAY "IWORK".

RPAR  Double

 

offset_rpar  Int32

 

IPAR  Int32

 

offset_ipar  Int32

 

IDID  Int32

REPORTS ON SUCCESSFULNESS UPON RETURN: IDID= 1 COMPUTATION SUCCESSFUL, IDID= 2 COMPUT. SUCCESSFUL (INTERRUPTED BY SOLOUT) IDID=-1 INPUT IS NOT CONSISTENT, IDID=-2 LARGER NMAX IS NEEDED, IDID=-3 STEP SIZE BECOMES TOO SMALL. IDID=-4 PROBLEM IS PROBABLY STIFF (INTERRUPTED).

Reference