anchor.diff:          if (present(longitude_system)) then
               if (longitude_system == kMAINTAIN_LON) then
                   ! break
  +            elseif (longitude_system == kDATELINE_CENTERED) then
  +                where(domain%lon<0) domain%lon = 360+domain%lon
               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
  
positive.code:                 ! lastpos%x = 1
                  ! lastpos%y = 1
                  write(*,*) "Error in Geographic interpolation, check input lat / lon grids", ims,j
                  stop
              endif
  
              do i = ims, ime
  
negative.code:                 write(*,*) " Set options%parameters%longitude_system to either:"
                  write(*,*) " Prime meridian centered (0 to 360): ", kPRIME_CENTERED
                  write(*,*) " Dateline meridian centered (-180 to 180): ", kDATELINE_CENTERED
                  error stop
              endif
          endif
  
  