C======================================================================
C         V E C T O R    H A N D L I N G  (grid-oriented operations)
C======================================================================
C----------------------------------------------------------------------
c nullv0:   V(.,.) <--  0.0d0 ;
C----------------------------------------------------------------------
      subroutine nullv(V, N1,N2)
      IMPLICIT none
      double precision V
      integer*4 i,j,N1,N2
      dimension V(N1,N2)

      do j=1,N2
         do i=1,N1
            V(i,j) = 0.0d0
         enddo
      enddo

      return
      end
C----------------------------------------------------------------------
c nullvi:   P(.,.) <--  0 ;  integer zeroing
C----------------------------------------------------------------------
      subroutine nullvi(P, N1, N2)
      IMPLICIT none
      integer*4 i,j,N1,N2,P
      DIMENSION P(N1,N2)

      do j=1,N2
         do i=1,N1
            P(i,j) = 0
         enddo
      enddo

      return
      end
C----------------------------------------------------------------------
c vvsub:   V1(.,.) <--  V2(.,.) - V3(.,.) ;
C----------------------------------------------------------------------
      subroutine vvsub(V1, V2, V3, N1, N2)
      IMPLICIT none
      double precision    V1, V2, V3
      integer*4 i,j, N1,N2
      DIMENSION V1(N1,N2), V2(N1,N2), V3(N1,N2)
C
      do j=1,N2
         do i=1,N1
          V1(i,j) = V2(i,j) - V3(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
c vminv:   V(.,.) = - W(.,.)
C-----------------------------------------------------------------------
      subroutine vminv(V, W, N1,N2)
      IMPLICIT none
      double precision V,W
      integer*4 i,j,N1,N2
      DIMENSION V(N1,N2), W(N1,N2)

      do j=1,N2
         do i=1,N1
          V(i,j) = - W(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
c vvcopy:   V(.,.) = W(.,.)
C-----------------------------------------------------------------------
      subroutine vvcopy(V, W, N1,N2)
      IMPLICIT none
      double precision V,W
      integer*4 i,j,N1,N2
      DIMENSION V(N1,N2), W(N1,N2)

      do j=1,N2
         do i=1,N1
          V(i,j) = W(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
c vimbed:   V(.,.) <-- W(.,.)
C-----------------------------------------------------------------------
      subroutine vimbed(V, W, N1,N2)
      IMPLICIT none
      double precision V,W
      integer*4 i,j,N1,N2
      DIMENSION V(0:N1+1,0:N2+1), W(N1,N2)

      call nullv(V,N1+2,N2+2)
      do j=1,N2
         do i=1,N1
          V(i,j) = W(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
c vimbedi:   P(.,.) <-- O(.,.)
C-----------------------------------------------------------------------
      subroutine vimbedi(P, O, N1,N2)
      IMPLICIT none
      integer O,P
      integer*4 i,j,N1,N2
      DIMENSION P(0:N1+1,0:N2+1), O(N1,N2)

      call nullvi(P,N1+2,N2+2)
      do j=1,N2
         do i=1,N1
          P(i,j) = O(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
c vpabsv:    V(.,.) <--- V(.,.) + a*W(.,.)
C-----------------------------------------------------------------------
      subroutine vpabsv(V, a, W, N1,N2)
      IMPLICIT none
      double precision V,W,a
      integer*4 i,j,N1,N2
      DIMENSION V(N1,N2), W(N1,N2)

      do j=1,N2
         do i=1,N1
          V(i,j) = V(i,j) + a*W(i,j)
         enddo
      enddo

      return
      end
C-----------------------------------------------------------------------
C vminsv:        Z(.,.) = -X(.,.) + a * Y(.,.)
C-----------------------------------------------------------------------
      subroutine vminsv(Z, X, a, Y, N1, N2)
      IMPLICIT none
      DOUBLE PRECISION X,Y,Z,a
      integer*4 i,j,N1,N2
      DIMENSION Z(N1,N2), X(N1,N2), Y(N1,N2)

      do j=1,N2
         do i=1,N1
          Z(i,j) = -X(i,j) + a*Y(i,j)
         enddo
      enddo

      return
      end