--- a/inst/io/private/ruledSurfGeo.m
+++ b/inst/io/private/ruledSurfGeo.m
@@ -1,15 +1,15 @@
 ## Copyright (C) 2012 Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
-## 
+##
 ## This program is free software; you can redistribute it and/or modify it under
 ## the terms of the GNU General Public License as published by the Free Software
 ## Foundation; either version 3 of the License, or (at your option) any later
 ## version.
-## 
+##
 ## This program is distributed in the hope that it will be useful, but WITHOUT
 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 ## details.
-## 
+##
 ## You should have received a copy of the GNU General Public License along with
 ## this program; if not, see <http://www.gnu.org/licenses/>.
 
@@ -20,17 +20,17 @@
 ## Creates a ruled surface with identifier @var{id}, i.e., a surface that can be
 ## interpolated using transfinite interpolation. @var{nloop} indicates the number
 ## of loops that define the surface. @var{loops} should contain the identification
-## number of a line loop composed of either three or four elementary lines. 
+## number of a line loop composed of either three or four elementary lines.
 ## @var{centerid} is the identification number of the center of the sphere, this
-## forces the surface to be a spherical patch. 
+## forces the surface to be a spherical patch.
 ##
 ## @end deftypefn
 
 function str = ruledSurfGeo(id,nloop,loops,centerid)
-    substr = repmat(',#d',1,nloop-1);
+    substr = repmat(',%d',1,nloop-1);
 
     if ~isempty(centerid)
-        str = sprintf(['Ruled Surface(#d) = {#d' substr '} In Sphere {#d};\n'], ...
+        str = sprintf(['Ruled Surface(%d) = {%d' substr '} In Sphere {%d};\n'], ...
                                                                  id,loops,centerid);
     else
         error('data2geo:Error',"The id of the centers shouldn't be empty");