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      subroutine dlwqh3 ( noseg  , nosys  , notot  , nobnd  , isys   ,
     &                    deriv  , bound  , rhs    , diag   , sol    )

!     Deltares Software Center

!     Created    : February 1997 by RJVos (like dlwqf4 from scheme 15)

!     Function   : put boundaries and derivatives in right hand side

!     Modified   : July 2008, Leo Postma  : WAQ performance timers
!                  June 2010, Leo Postma  : double precission version

!     File I/O   : none

!     Subroutines: none

      use timers                         ! WAQ performance timers

      implicit none

!     Arguments           :

!     Kind        Function         Name                  Description

      integer(4), intent(in   ) :: noseg               ! Number of computational volumes
      integer(4), intent(in   ) :: nosys               ! Number of transported substances
      integer(4), intent(in   ) :: notot               ! Total number of substances
      integer(4), intent(in   ) :: nobnd               ! Number of boundaries
      integer(4), intent(in   ) :: isys                ! This substance
      real   (4), intent(in   ) :: deriv(notot,noseg)  ! Derivatives
      real   (4), intent(in   ) :: bound(nosys,nobnd)  ! Open boundary values
      real   (8), intent(inout) :: rhs  (noseg+nobnd)  ! Right hand side of the equation
      real   (8), intent(in   ) :: diag (noseg+nobnd)  ! diagonal for scaling
      real   (8), intent(  out) :: sol  (noseg+nobnd)  ! initial guess for solution

!     Local variables

      integer(4) iseg       ! loop counter

      integer(4) ithandl /0/
      if ( timon ) call timstrt ( "dlwqh3", ithandl )

!        initialize the rhs and apply row scaling

      do iseg = 1 , noseg
         rhs(iseg) = deriv(isys,iseg) / diag(iseg)
      enddo
      do iseg = 1 , nobnd
         rhs(iseg+noseg) = bound(isys,iseg)
      enddo

!        zero initial guess, try rhs plus small value

      sol = 0.0
      do iseg = 1, noseg
         sol(iseg) = rhs(iseg) + 0.01
      enddo

      if ( timon ) call timstop ( ithandl )
      RETURN
      END