anchor.diff:          logical,                intent(in),   optional :: boundary_only
   
           integer :: ims,ime, jms,jme, kms,kme
  -        integer:: i,j,k,l, localx,localy
  +        integer:: i,j,k,l, localx,localy, nz_input
           logical :: boundaries
           real :: localw
           real :: local_center
  
positive.code:                         do l=1,4
                              localx=geolut%x(l,i,k)
                              localy=geolut%y(l,i,k)
                              local_center = local_center + fieldin(localx,j,localy)
                              ! This is the actual interpolation adding the value from the two raw grid points
                              if (l < 3) then
                                  localw=geolut%w(l,i,k)
                                  fieldout(i,j,k) = fieldout(i,j,k) + fieldin(localx,j,localy) * localw
                              endif
                          enddo
                          ! This is the actual interpolation adding the value from the center average of all four grid points
  
negative.code:         jme = ubound(fieldout,2)
          kms = lbound(fieldout,3)
          kme = ubound(fieldout,3)
  
          nz_input = size(fieldin,2)
  
          boundaries = .False.
          if (present(boundary_only)) boundaries = boundary_only
  