| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer | :: | NEQ | ||||
| real(kind=r64) | :: | H | ||||
| real(kind=r64) | :: | X | ||||
| real(kind=r64), | DIMENSION(NEQ) | :: | Y | |||
| real(kind=r64), | DIMENSION(NEQ) | :: | DY | |||
| real(kind=r64), | DIMENSION(NEQ) | :: | C |
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed arrows point from an interface to procedures which implement that interface. This could include the module procedures in a generic interface or the implementation in a submodule of an interface in a parent module. Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed arrows point from an interface to procedures which implement that interface. This could include the module procedures in a generic interface or the implementation in a submodule of an interface in a parent module. Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.
SUBROUTINE RKG(NEQ,H,X,Y,DY,C)
! SUBROUTINE INFORMATION:
! AUTHOR Jaewook Lee
! DATE WRITTEN January 2000
! MODIFIED Rick Strand (for E+ implementation February 2000)
! RE-ENGINEERED na
! PURPOSE OF THIS SUBROUTINE:
! This is a subroutine for integration by Runga-Kutta's method.
! METHODOLOGY EMPLOYED:
! This subroutine is based heavily upon the work performed by Dan Maloney for
! the BLAST program. Many of the equations are based on the original Pierce
! development. See documentation for further details and references.
! REFERENCES:
! Maloney, Dan, M.S. Thesis, University of Illinois at Urbana-Champaign
! USE STATEMENTS:
! na
IMPLICIT NONE ! Enforce explicit typing of all variables in this routine
! SUBROUTINE ARGUMENT DEFINITIONS:
! na
! SUBROUTINE PARAMETER DEFINITIONS:
! na
! INTERFACE BLOCK SPECIFICATIONS:
! na
! DERIVED TYPE DEFINITIONS:
! na
! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
INTEGER :: I
INTEGER :: J
INTEGER :: NEQ
REAL(r64) :: B
REAL(r64) :: H
REAL(r64) :: H2
REAL(r64) :: X
REAL(r64), DIMENSION(2) :: A
REAL(r64), DIMENSION(NEQ) :: C
REAL(r64), DIMENSION(NEQ) :: DY
REAL(r64), DIMENSION(NEQ) :: Y
A(1) = 0.29289321881345d0
A(2) = 1.70710678118654d0
H2 = .5d0*H
CALL DERIV (NEQ,Y,DY)
DO I = 1,NEQ
B = H2*DY(I) - C(I)
Y(I) = Y(I) + B
C(I) = C(I) + 3.d0*B - H2*DY(I)
END DO
X = X + H2
DO J = 1,2
CALL DERIV (NEQ,Y,DY)
DO I = 1,NEQ
B = A(J)*(H*DY(I) - C(I))
Y(I) = Y(I) + B
C(I) = C(I) + 3.d0*B - A(J)*H*DY(I)
END DO
END DO
X = X + H2
CALL DERIV (NEQ,Y,DY)
DO I = 1,NEQ
B = (H*DY(I) - 2.d0*C(I))/6.0d0
Y(I) = Y(I) + B
C(I) = C(I) + 3.d0*B - H2*DY(I)
END DO
CALL DERIV (NEQ,Y,DY)
RETURN
END SUBROUTINE RKG