, ÿÿÿÿ 9S    ð  ð      í   ß   differentiate_center4 1 gridset  / DimXMin/ DimXMax/ DimZMin/ DimZMax/ DelX/ DelZ0xz_dx_pz 	       @  xz_dx_pz
    @  €                      pz_var
  A      €                      xz_dz_xr 	         @  xz_dz_xr
    @  €                      xr_var
  A      €                      pz_dx_xz 	         @  pz_dx_xz
    @  €                      xz_var
  A      €                      pz_dz_pr 	         @  pz_dz_pr
    @  €                      pr_var
  A      €                      xr_dx_pr 	         @  xr_dx_pr
    @  €                      pr_var
  A      €                      xr_dz_xz 	         @  xr_dz_xz
    @  €                      xz_var
  A      €                      pr_dx_xr 	         @  pr_dx_xr
    @  €                      xr_var
  A      €                      pr_dz_pz 	         @  pr_dz_pz
    @  €                      pz_var
  A      €                       