anchor.diff:                                   spatial_linear_fields, linear_mask, nsq_calibration, &
                                    dirmax, dirmin, spdmax, spdmin, nsqmax, nsqmin, n_dir_values, n_nsq_values, n_spd_values, &
                                    read_LUT, write_LUT, u_LUT_Filename, v_LUT_Filename, overwrite_lt_lut, LUT_Filename
  -        
  +
            ! because lt_options could be in a separate file
            if (options%use_lt_options) then
                if (trim(filename)/=trim(get_options_file())) then
                    call version_check(filename,options)
                endif
            endif
  -        
  -        
  +
  +
           ! set default values
           variable_N = .True.
           smooth_nsq = .False.
  
positive.code:         implicit none
          character(len=*), intent(in) :: filename
          type(options_type), intent(inout) :: options
          
          integer :: name_unit, this_level
          real, allocatable, dimension(:) :: dz_levels
          real, dimension(45) :: fulldz
          
          namelist /z_info/ dz_levels
          this_level=1
  
  
negative.code:                                         soiltype_var, soil_t_var,soil_vwc_var,soil_deept_var,           &
                                          vegtype_var,vegfrac_var, linear_mask_var, nsq_calibration_var,  &
                                          swdown_var, lwdown_var, sst_var, rain_var
  
          namelist /var_list/ pvar,pbvar,tvar,qvvar,qcvar,qivar,hgtvar,shvar,lhvar,pblhvar,   &
                              landvar,latvar,lonvar,uvar,ulat,ulon,vvar,vlat,vlon,zvar,zbvar, &
                              hgt_hi,lat_hi,lon_hi,ulat_hi,ulon_hi,vlat_hi,vlon_hi,           &
                              soiltype_var, soil_t_var,soil_vwc_var,soil_deept_var,           &
                              vegtype_var,vegfrac_var, linear_mask_var, nsq_calibration_var,  &
                              swdown_var, lwdown_var, sst_var, rain_var
  
          hgtvar="HGT"
          latvar="XLAT"
          lonvar="XLONG"
  