reconstruct_kmin Subroutine

    subroutine reconstruct_kmin(qp, scheme, bc)
      !< Reconstruct state at the KMIN boundary face with MUSCL scheme

      implicit none
      real(wp), dimension(-2:imx+2, -2:jmx+2, -2:kmx+2, 1:n_var), intent(in) :: qp
      type(schemetype), intent(in) :: scheme
      type(boundarytype), intent(in) :: bc
      real(wp) :: psi1, psi2, fd, bd, r
      integer :: i, j, k, l
      real(wp) :: kappa, phi
      
      phi = 1.0
      kappa = 1./3.
      switch_L=scheme%klimiter_switch

      if (ppm_flag==1) then
        do k = 1, 1
         do l = 1, n_var
           if(l>=6) switch_L=scheme%ktlimiter_switch
           if(l<6) switch_L=scheme%klimiter_switch
          do j = 1, jmx - 1
           do i = 1, imx - 1

              fd = qp(i, j, k+1, l) - qp(i, j, k, l)
              bd = qp(i, j, k, l) - qp(i, j, k-1, l)

              r = fd / bd
              psi1 = max(0., min(2*r, (2 + r)/3., 2.))
              psi1 = (1 - (1 - psi1)*switch_L )
              r = bd / fd
              psi2 = max(0., min(2*r, (2 + r)/3., 2.))
              psi2 = (1 - (1 - psi2)*switch_L )
              
              ! right face of first k cell
              z_qp_left(i, j, k+1, l) = qp(i, j, k, l) + 0.25*phi* &
                  (((1-kappa) * psi1 * bd) + ((1+kappa) * psi2 * fd))

              ! left face of first k cell
              z_qp_right(i, j, k, l) = qp(i, j, k, l) - 0.25*phi* &
                  (((1+kappa) * psi1 * bd) + ((1-kappa) * psi2 * fd))
           end do
          end do
         end do
        end do
      end if
      if(bc%kmin_id==-8 .or. bc%kmin_id==-9)then
         z_qp_left(1:imx-1,1:jmx-1,1,1:n_var) = qp(1:imx-1,1:jmx-1,0,1:n_var) 
        z_qp_right(1:imx-1,1:jmx-1,1,1:n_var) = qp(1:imx-1,1:jmx-1,0,1:n_var) 
      else
         z_qp_left(1:imx-1,1:jmx-1,1,1:n_var) = 0.5*(qp(1:imx-1,1:jmx-1,0,1:n_var)&
                                                    +qp(1:imx-1,1:jmx-1,1,1:n_var))
      end if

    end subroutine reconstruct_kmin