subroutine sweepbc(nleft,nright)
C
C Impose boundary conditions on ends of 1D sweep arrays
C
C-----------------------------------------------------------------------
C
C GLOBALS
C
      include 'global.h'
      include 'sweep.h'
C
C LOCALS
C
      integer nleft, nright
C
C-----------------------------------------------------------------------
C
C  Boundary condition flags : nleft, nright
C    = 0 : reflecting
C    = 1 : outflow (zero gradients)
C    = 2 : fixed inflow (eg, uinflo,pinflo,...)
C    = 3 : periodic (eg, u(nmin-1) = u(nmax))
C    = 5 : your own recipe
C
      if ( nleft .eq. 0 ) then
        dx (nmin-1) = dx (nmin)
        dx (nmin-2) = dx (nmin+1)
        xa (nmin-1) = xa (nmin)   - dx(nmin-1)
        xa (nmin-2) = xa (nmin-1) - dx(nmin-2)
        rho(nmin-1) = rho(nmin)
        rho(nmin-2) = rho(nmin+1)
        u  (nmin-1) = -u (nmin)
        u  (nmin-2) = -u (nmin+1)
        v  (nmin-1) = v  (nmin)
        v  (nmin-2) = v  (nmin+1)
        w  (nmin-1) = w  (nmin)
        w  (nmin-2) = w  (nmin+1)
        p  (nmin-1) = p  (nmin)
        p  (nmin-2) = p  (nmin+1)
      else if ( nleft .eq. 1 ) then
        dx (nmin-1) = dx (nmin)
        dx (nmin-2) = dx (nmin)
        xa (nmin-1) = xa (nmin)   - dx(nmin-1)
        xa (nmin-2) = xa (nmin-1) - dx(nmin-2)
        rho(nmin-1) = rho(nmin)
        rho(nmin-2) = rho(nmin)
        u  (nmin-1) = u  (nmin)
        u  (nmin-2) = u  (nmin)
        v  (nmin-1) = v  (nmin)
        v  (nmin-2) = v  (nmin)
        w  (nmin-1) = w  (nmin)
        w  (nmin-2) = w  (nmin)
        p  (nmin-1) = p  (nmin)
        p  (nmin-2) = p  (nmin)
      else if ( nleft .eq. 2 ) then
        dx (nmin-1) = dx (nmin)
        dx (nmin-2) = dx (nmin)
        xa (nmin-1) = xa (nmin)   - dx(nmin-1)
        xa (nmin-2) = xa (nmin-1) - dx(nmin-2)
        rho(nmin-1) = dinflo
        rho(nmin-2) = dinflo
        u  (nmin-1) = uinflo
        u  (nmin-2) = uinflo
        v  (nmin-1) = vinflo
        v  (nmin-2) = vinflo
        w  (nmin-1) = winflo
        w  (nmin-2) = winflo
        p  (nmin-1) = pinflo
        p  (nmin-2) = pinflo
      else if ( nleft .eq. 3 ) then
        dx (nmin-1) = dx (nmax)
        dx (nmin-2) = dx (nmax-1)
        xa (nmin-1) = xa (nmin)   - dx(nmin-1)
        xa (nmin-2) = xa (nmin-1) - dx(nmin-2)
        rho(nmin-1) = rho(nmax)
        rho(nmin-2) = rho(nmax-1)
        u  (nmin-1) = u  (nmax)
        u  (nmin-2) = u  (nmax-1)
        v  (nmin-1) = v  (nmax)
        v  (nmin-2) = v  (nmax-1)
        w  (nmin-1) = w  (nmax)
        w  (nmin-2) = w  (nmax-1)
        p  (nmin-1) = p  (nmax)
        p  (nmin-2) = p  (nmax-1)
      else if ( nleft .eq. 5 ) then
        dx (nmin-1) = dx (nmin)
        dx (nmin-2) = dx (nmin)
        xa (nmin-1) = xa (nmin)   - dx(nmin-1)
        xa (nmin-2) = xa (nmin-1) - dx(nmin-2)
        rho(nmin-1) = dinflo
        rho(nmin-2) = dinflo
        u  (nmin-1) = vinflo
        u  (nmin-2) = vinflo
        v  (nmin-1) = winflo
        v  (nmin-2) = winflo
        w  (nmin-1) = uinflo
        w  (nmin-2) = uinflo
        p  (nmin-1) = pinflo
        p  (nmin-2) = pinflo
      endif
C
      if ( nright .eq. 0 ) then     
        dx (nmax+1) = dx (nmax)
        dx (nmax+2) = dx (nmax-1)
        xa (nmax+2) = xa (nmax+1) + dx(nmax+1)
        rho(nmax+1) = rho(nmax)
        rho(nmax+2) = rho(nmax-1)
        u  (nmax+1) = -u (nmax)
        u  (nmax+2) = -u (nmax-1)
        v  (nmax+1) = v  (nmax)
        v  (nmax+2) = v  (nmax-1)
        w  (nmax+1) = w  (nmax)
        w  (nmax+2) = w  (nmax-1)
        p  (nmax+1) = p  (nmax)
        p  (nmax+2) = p  (nmax-1)
      else if ( nright .eq. 1 ) then     
        dx (nmax+1) = dx (nmax)
        dx (nmax+2) = dx (nmax)
        xa (nmax+2) = xa (nmax+1) + dx(nmax+1)
        rho(nmax+1) = rho(nmax)
        rho(nmax+2) = rho(nmax)
        u  (nmax+1) = u  (nmax)
        u  (nmax+2) = u  (nmax)
        v  (nmax+1) = v  (nmax)
        v  (nmax+2) = v  (nmax)
        w  (nmax+1) = w  (nmax)
        w  (nmax+2) = w  (nmax)
        p  (nmax+1) = p  (nmax)
        p  (nmax+2) = p  (nmax)
      else if ( nright .eq. 2 ) then     
        dx (nmax+1) = dx (nmax)
        dx (nmax+2) = dx (nmax)
        xa (nmax+2) = xa (nmax+1) + dx(nmax+1)
        rho(nmax+1) = dinflo
        rho(nmax+2) = dinflo
        u  (nmax+1) = uinflo
        u  (nmax+2) = uinflo
        v  (nmax+1) = vinflo
        v  (nmax+2) = vinflo
        w  (nmax+1) = winflo
        w  (nmax+2) = winflo
        p  (nmax+1) = pinflo
        p  (nmax+2) = pinflo
      else if ( nright .eq. 3 ) then     
        dx (nmax+1) = dx (nmin)
        dx (nmax+2) = dx (nmin+1)
        xa (nmax+2) = xa (nmax+1) + dx(nmax+1)
        rho(nmax+1) = rho(nmin)
        rho(nmax+2) = rho(nmin+1)
        u  (nmax+1) = u  (nmin)
        u  (nmax+2) = u  (nmin+1)
        v  (nmax+1) = v  (nmin)
        v  (nmax+2) = v  (nmin+1)
        w  (nmax+1) = w  (nmin)
        w  (nmax+2) = w  (nmin+1)
        p  (nmax+1) = p  (nmin)
        p  (nmax+2) = p  (nmin+1)
      else if ( nright .eq. 5 ) then     
        dx (nmax+1) = dx (nmax)
        dx (nmax+2) = dx (nmax)
        xa (nmax+2) = xa (nmax+1) + dx(nmax+1)
        rho(nmax+1) = dinflo
        rho(nmax+2) = dinflo
        u  (nmax+1) = vinflo
        u  (nmax+2) = vinflo
        v  (nmax+1) = winflo
        v  (nmax+2) = winflo
        w  (nmax+1) = uinflo
        w  (nmax+2) = uinflo
        p  (nmax+1) = pinflo
        p  (nmax+2) = pinflo
      endif
C 
      return
      end