1 files changed, 9 insertions, 29 deletions
diff --git a/lib/axlsx/drawing/cat_axis_data.rb b/lib/axlsx/drawing/cat_axis_data.rb
index a119282e..ced5a305 100644
--- a/lib/axlsx/drawing/cat_axis_data.rb
+++ b/lib/axlsx/drawing/cat_axis_data.rb
@@ -13,38 +13,18 @@ module Axlsx
 
 
     def to_xml_string(str = '')
-      str << '<cat>'
-      str << '<strRef>'
-      str << '<f>' << Axlsx::cell_range(@list) << '</f>'
-      str << '<strCache>'
-      str << '<ptCount val="' << size.to_s << '"/>'
+      str << '<c:cat>'
+      str << '<c:strRef>'
+      str << '<c:f>' << Axlsx::cell_range(@list) << '</c:f>'
+      str << '<c:strCache>'
+      str << '<c:ptCount val="' << size.to_s << '"/>'
       each_with_index do |item, index|
         v = item.is_a?(Cell) ?  item.value.to_s : item
-        str << '<pt idx="' << index.to_s << '"><v>' << v << '</v></pt>'
+        str << '<c:pt idx="' << index.to_s << '"><c:v>' << v << '</c:v></c:pt>'
       end
-      str << '</strCache>'
-      str << '</strRef>'
-      str << '</cat>'
-    end
-
-    # Serializes the category axis data
-    # @param [Nokogiri::XML::Builder] xml The document builder instance this objects xml will be added to.
-    # @return [String]
-    def to_xml(xml)
-      xml.cat {
-        xml.strRef {
-          xml.f Axlsx::cell_range(@list)
-          xml.strCache {
-            xml.ptCount :val=>size
-            each_with_index do |item, index|
-              v = item.is_a?(Cell) ? item.value : item
-              xml.pt(:idx=>index) {
-                xml.v v
-              }
-            end
-          }
-        }
-      }
+      str << '</c:strCache>'
+      str << '</c:strRef>'
+      str << '</c:cat>'
     end
 
   end