anchor.diff:  
       !        -- Interieur --
   
  -        do i=2,pasx
  -            do j=2,pasy-1
  -                temp1=(eta(i-1,j)+eta(i+1,j)-2*eta(i,j))/(dx*dx)        &
  -                    +(eta(i,j-1)+eta(i,j+1)-2*eta(i,j))/(dy*dy)
  -                temp2=((eta(i+1,j)-eta(i-1,j))/(2*dx))**2               &
  -                    +((eta(i,j+1)-eta(i,j-1))/(2*dy))**2
  -                b(i,j)=(Bu+Ro*eta(i,j))*temp1+Ro/2*temp2
  -                q(i,j)=temp1
  +        do i = 2, pasx
  +            do j = 2, pasy-1
  +                temp1 = (eta(i-1,j)+eta(i+1,j)-2*eta(i,j))/(dx*dx)        &
  +                      + (eta(i,j-1)+eta(i,j+1)-2*eta(i,j))/(dy*dy)
  +                temp2 = ((eta(i+1,j)-eta(i-1,j))/(2*dx))**2               &
  +                      + ((eta(i,j+1)-eta(i,j-1))/(2*dy))**2
  +                b(i,j) = (Bu+Ro*eta(i,j))*temp1 + Ro/2*temp2
  +                q(i,j) = temp1
               end do
           end do
        
           !        -- Bords y --
   
  -        do i=2,pasx
  -            j=1
  -            temp1=(eta(i-1,j)+eta(i+1,j)-2*eta(i,j))/(dx*dx)   &
  -                +(eta(i,j)+eta(i,j+2)-2*eta(i,j+1))/(dy*dy)
  -            temp2=((eta(i+1,j)-eta(i-1,j))/(2*dx))**2  &
  -                 +((4*eta(i,j+1)-eta(i,j+2)-3*eta(i,j))/(2*dy))**2
  +        do i = 2, pasx
  +            j = 1
  +            temp1 = (eta(i-1,j)+eta(i+1,j)-2*eta(i,j))/(dx*dx)        &
  +                  + (eta(i,j)+eta(i,j+2)-2*eta(i,j+1))/(dy*dy)
  +            temp2 = ((eta(i+1,j)-eta(i-1,j))/(2*dx))**2               &
  +                  + ((4*eta(i,j+1)-eta(i,j+2)-3*eta(i,j))/(2*dy))**2
               b(i,j)=(Bu+Ro*eta(i,j))*temp1+Ro/2*temp2
               q(i,j)=temp1
               j=pasy
  -            temp1=(eta(i-1,j)+eta(i+1,j)-2*eta(i,j))/(dx*dx)   &
  -                 +(eta(i,j)+eta(i,j-2)-2*eta(i,j-1))/(dy*dy)
  -            temp2=((eta(i+1,j)-eta(i-1,j))/(2*dx))**2          &
  -            +((-4*eta(i,j-1)+eta(i,j-2)+3*eta(i,j))/(2*dy))**2
  -            b(i,j)=(Bu+Ro*eta(i,j))*temp1+Ro/2*temp2
  -            q(i,j)=temp1
  +            temp1 = (eta(i-1,j) + eta(i+1,j) - 2*eta(i,j))   /(dx*dx)   &
  +                  + (eta(i,j)   + eta(i,j-2) - 2*eta(i,j-1)) /(dy*dy)
  +            temp2 = ((eta(i+1,j)-eta(i-1,j))/(2*dx))**2          &
  +                  + ((-4*eta(i,j-1)+eta(i,j-2) + 3*eta(i,j))/(2*dy))**2
  +            b(i,j) = (Bu+Ro*eta(i,j))*temp1 + Ro/2*temp2
  +            q(i,j) = temp1
           end do
        
           !        -- Ajout des lignes i=1 et i=pasx+1 --
   
  -        do j=1,pasy
  -            b(1,j)=b(pasx,j)
  -            b(pasx+1,j)=b(2,j)
  -            q(1,j)=q(pasx,j)
  -            q(pasx+1,j)=q(2,j)
  +        do j = 1, pasy
  +            b(1,j) = b(pasx,j)
  +            b(pasx+1,j) = b(2,j)
  +            q(1,j) = q(pasx,j)
  +            q(pasx+1,j) = q(2,j)
           end do
   
   !        ------------------------     
  
positive.code:         x(i) = (i-2)*dx
      end do
  
      x(1)=x(pasx)
      x(2)=x(pasx+1)
  
      do j=1,pasy      
          y(j)=-Ly+(j-1)*dy
      end do
  
      temp1 = g*h0/f/L/U
      do i=1,pasx+1
          temp2 = 0.01*sin(pi*x(i)/Lx)
          do j=1,pasy
              if(abs(y(j)).LT.1) then
                  eta(i,j)=temp1*temp2-0.5*y(j)**2*(1+temp2)
              else
                  eta(i,j)=temp1*temp2+(0.5-abs(y(j)))*(1+temp2)
              endif
          end do
      end do
  
negative.code: 
      open (UNIT = 1, FILE = 'res.m', STATUS ='unknown')
  
      do i = 2, pasx+1
          do j = 1, pasy
              write(1,*) 'a(', (save-1)*pasx+i-1, ',', j, ')=', eta(i,j), ';'
          end do
      end do
  
  