anchor.diff:              write(*,*) x2, y2
               write(*,*) x3, y3
               write(*,*) w1, w2, w3
  -            stop "Triangulation is broken"
  +            error stop "Triangulation is broken"
           endif
           w1=max(0.,w1); w2=max(0.,w2); w3=max(0.,w3);
   
  
positive.code:         if (present(longitude_system)) then
              if (longitude_system == kMAINTAIN_LON) then
                  ! break
              elseif (longitude_system == kPRIME_CENTERED) then
                  where(domain%lon<0) domain%lon = 360+domain%lon
              elseif (longitude_system == kDATELINE_CENTERED) then
                  where(domain%lon>180) domain%lon = domain%lon - 360
              elseif (longitude_system == kGUESS_LON) then
                  ! try to guess which coordinate system to use
  
negative.code:                 ! lastpos%x = 1
                  ! lastpos%y = 1
                  write(*,*) "Error in Geographic interpolation, check input lat / lon grids", ims,j
                  error stop
              endif
  
              do i = ims, ime
  