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!----------------------------------------------------------------------
!----------------------------------------------------------------------
! bru : Time integration of a scalar nonlinear parabolic PDE
!----------------------------------------------------------------------
!----------------------------------------------------------------------
SUBROUTINE FUNC(NDIM,U,ICP,PAR,IJAC,F,DFDU,DFDP)
! ---------- ----
IMPLICIT NONE
INTEGER, INTENT(IN) :: NDIM, ICP(*), IJAC
DOUBLE PRECISION, INTENT(IN) :: U(NDIM), PAR(*)
DOUBLE PRECISION, INTENT(OUT) :: F(NDIM)
DOUBLE PRECISION, INTENT(INOUT) :: DFDU(NDIM,NDIM), DFDP(NDIM,*)
DOUBLE PRECISION X,Y,A,B
X=U(1)
Y=U(2)
A=PAR(1)
B=PAR(2)
! *Set the nonlinear term
F(1)= X**2*Y - (B+1)*X + A
F(2)=-X**2*Y + B*X
END SUBROUTINE FUNC
SUBROUTINE STPNT(NDIM,U,PAR,Z)
! ---------- -----
IMPLICIT NONE
INTEGER, INTENT(IN) :: NDIM
DOUBLE PRECISION, INTENT(INOUT) :: U(NDIM),PAR(*)
DOUBLE PRECISION, INTENT(IN) :: Z
DOUBLE PRECISION pi,A,B,Dx,Dy,RL
pi=4*DATAN(1.d0)
! *Set the (constant) parameters
A = 2.
B = 5.45
Dx = 0.008
Dy = 0.004
RL = 0.75
PAR(1)=A
PAR(2)=B
PAR(3)=RL
! *Set the actual width of the space interval [0,PAR(11)]
PAR(11) = 1.
! *Set the initial data in the (scaled) interval [0,1]
U(1) = A - 0.5*DSIN(pi*Z)
U(2) = B/A + 0.7*DSIN(pi*Z)
! *Also set the space-derivative of the initial data
! *Note the scaling by PAR(11)
U(3) = - 0.5*pi*DCOS(pi*Z)/PAR(11)
U(4) = 0.7*pi*DCOS(pi*Z)/PAR(11)
! *Set the diffusion constants
PAR(15) = Dx/RL**2
PAR(16) = Dy/RL**2
END SUBROUTINE STPNT
SUBROUTINE BCND(NDIM,PAR,ICP,NBC,U0,U1,FB,IJAC,DBC)
! ---------- ----
IMPLICIT NONE
INTEGER, INTENT(IN) :: NDIM, ICP(*), NBC, IJAC
DOUBLE PRECISION, INTENT(IN) :: PAR(*), U0(NDIM), U1(NDIM)
DOUBLE PRECISION, INTENT(OUT) :: FB(NBC)
DOUBLE PRECISION, INTENT(INOUT) :: DBC(NBC,*)
! *Define the boundary conditions (Dirichlet, in this example).
FB(1)=U0(1)-PAR(1)
FB(2)=U0(2)-PAR(2)/PAR(1)
FB(3)=U1(1)-PAR(1)
FB(4)=U1(2)-PAR(2)/PAR(1)
END SUBROUTINE BCND
SUBROUTINE ICND
END SUBROUTINE ICND
SUBROUTINE FOPT
END SUBROUTINE FOPT
SUBROUTINE PVLS
END SUBROUTINE PVLS
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