anchor.diff:  alpha=st*sigma*vth*sfwc**beta/2./svg
   g=nt*2.*svg/sfwc**beta
   
  -DO j=1,ydim
  +DO j=1,xdim
      gamm = g * REAL(j)
      DO k=1,zdim
         IF(tr(k).lt.t)THEN
  -         DO i=1,xdim
  +         DO i=1,ydim
               nc=0.
               
               IF(s(i,j).gt.0.01)THEN
  
positive.code: alpha=t*sigma*vth*fwc**beta/2./vg
  g=nt*2.*vg/fwc**beta
  
  DO i=1,xdim
     gamm = g * REAL(i)
     DO k=1,zdim
        DO j=1,ydim
           nc=0.
           
           IF(s(i,j).gt.0.01)THEN
  
negative.code: ! flip data back to the input orientation
  DO i=1,xdim
     DO j=1,ydim
        sout(i+iflip*(xdim+1-2*i),j+jflip*(ydim+1-2*j)) = s(j,i)
     ENDDO
  ENDDO
  
  