anchor.diff:              enddo
           enddo
   
  -    end subroutine  geo_interp2d
  +    end subroutine
   
   
       subroutine standardize_coordinates(domain)
  
positive.code:         type(fourpos) :: xy
          type(position) :: curpos, lastpos
          integer :: nx, ny, i, j, k, lo_nx, lo_ny
          real, dimension(4) :: lat, lon
  
          nx    = size(hi%lat,1)
  
negative.code:         xc = lastpos%x
          yc = lastpos%y
  
          x = lo%lon(xc, yc)
          y = lo%lat(xc, yc)
  
          ! steps to take = the difference the between the current point and the input point / dx
          xstep = (lon-x)/dx
          ystep = (lat-y)/dy
  
          ! CASE 1 assume a quasi regular dx/dy and calculate new location
          !  while we need to step by more than one grid cell, iterate
          !  if the grid is highly regular, we will only iterate 1-2x, highly irregular might require more iterations
          !  in the diabolical case, this could fail?
  